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RE: [bmw e28] Digest Number 567

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  • Stuart Logan
    The Speedo is electronic in these cars, so any work to the rear axle, - specifically the transducer as you call it, would be the direct cause of these
    Message 1 of 2 , Jun 15, 2004
      The Speedo is electronic in these cars, so any work to the rear axle, -
      specifically the 'transducer' as you call it, would be the direct cause of
      these issues.

      Also, the Fuel economy gauge is NOT a Vacuum gauge of any sort. It is a
      relatively direct display from the Engine FI Computer showing fuel delivery
      rate .vs. speed (from) the 'tempo' signal generated by the hall effect unit
      in the rear axle (the same unit that supplies the Speedo, OBC, and Cruise
      Control).

      Stuart Logan
      '83 528e
      '84 528e
      '85 535i
      '82 733i

      -----Original Message-----



      ________________________________________________________________________
      ________________________________________________________________________

      Message: 1
      Date: Mon, 14 Jun 2004 19:42:44 -0000
      From: "sheetfar" <sheetfar@...>
      Subject: obc/speedo don't work

      I have a 1986 528e with a manual transmission.

      Recently, the following things have started to malfunction:

      * Speedometer doesn't work.

      * White-needle vacuum gage (located just below tach) doesn't work.

      * On Board Computer OBC works except for the fuel consumption &
      driving speed (MPG & MPH buttons).

      After driving the car for 20 minutes or so, the vacuum gage starts
      cycling on/off every 2 seconds. Eventually, the speedometer might
      work after the vac gage starts working properly.

      I replaced the expansion valve on the A/C evaporator last month.
      However, everything (all instruments were checked) worked fine after
      that.

      The most recent work was done several days ago on the rear axle
      portion of the car. If the differential transducer has a bad
      connection or has malfunctioned, could it cause any of the
      speedo/vac gage/OBC problems?



      ________________________________________________________________________
      ________________________________________________________________________

      Message: 2
      Date: Mon, 14 Jun 2004 20:03:34 -0000
      From: "sheetfar" <sheetfar@...>
      Subject: a/c starts out cold, then heats up

      I have a 1986 528e.

      What would cause the air conditioning to work fine for about 15
      minutes or so, then start heating up slowly?

      This occurs under the following conditions:
      * Air vents closed (no outside air leaking in).
      * Temp switch set to coldest (rotated CCW).
      * A/C fan speed set to medium or high (2 or 3).
      * Outside temp above 90 deg F. (It doesn't seem to act up until the
      outside temp is hot).
      * Inside air vent (vent above radio) temp starts out at 42 deg F,
      then slowly works its way up to maybe 55 deg F.

      What I did so far:
      * Replaced the expansion valve on the evaporator.

      The low & high side pressure readings seem ok (20 or so psi low
      side, and 225 high side. The compressor seems ok, since it cycles
      off at around 335 psi when the engine revs up. All the gage readings
      appear to be normal.

      The heater control valve is working fine.

      I heard that the evaporator temp sensor on the earlier models could
      cause icing under certain conditions (Bentley). One parts supplier
      mentioned the possibility of a bad temp regulator.

      Any thoughts?



      ________________________________________________________________________
      ________________________________________________________________________

      Message: 3
      Date: Mon, 14 Jun 2004 13:30:52 -0700 (PDT)
      From: Ron Kall <ronjkall@...>
      Subject: Re: a/c starts out cold, then heats up

      A/C problem - you did not mention how old the freon
      was? this car is R12. some not so good shops have been
      know to put R134a into these R12 systems instead. i
      watched my guy dump 3 lbs. into mine in a shop in LA
      and I made sure it was R12. Good work and cold as ice.
      older systems get looser and leak. belt slippage on
      the compressor pump as the engine heats up? a/c can
      cease to be cool if airflow goes down - stuck in
      traffic or stopped, but mine would always get colder
      as i went longer and faster. good luck.

      Ron Kall

      1986 528e
      1985 535i

      --- sheetfar <sheetfar@...> wrote:
      > I have a 1986 528e.
      >
      > What would cause the air conditioning to work fine
      > for about 15
      > minutes or so, then start heating up slowly?
      >
      > This occurs under the following conditions:
      > * Air vents closed (no outside air leaking in).
      > * Temp switch set to coldest (rotated CCW).
      > * A/C fan speed set to medium or high (2 or 3).
      > * Outside temp above 90 deg F. (It doesn't seem to
      > act up until the
      > outside temp is hot).
      > * Inside air vent (vent above radio) temp starts out
      > at 42 deg F,
      > then slowly works its way up to maybe 55 deg F.
      >
      > What I did so far:
      > * Replaced the expansion valve on the evaporator.
      >
      > The low & high side pressure readings seem ok (20 or
      > so psi low
      > side, and 225 high side. The compressor seems ok,
      > since it cycles
      > off at around 335 psi when the engine revs up. All
      > the gage readings
      > appear to be normal.
      >
      > The heater control valve is working fine.
      >
      > I heard that the evaporator temp sensor on the
      > earlier models could
      > cause icing under certain conditions (Bentley). One
      > parts supplier
      > mentioned the possibility of a bad temp regulator.
      >
      > Any thoughts?
      >
      >





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      Message: 4
      Date: Mon, 14 Jun 2004 14:12:41 -0700 (PDT)
      From: Joel Trevino Gonzalez <purplehead2002@...>
      Subject: Re: obc/speedo don't work

      Most definitely check out the area where work was done as your
      speedometer doesn't work correctly. Check and make sure everything is
      tighten up correctly and that the wires are connected back correctly to the
      correct screw towers/connection points.

      How long has your speedometer not been working? Did it happen right
      after that work on the car? Did you go over some debris on the road that
      might have put it out of order?

      I hope this helps somewhat,

      Joel Gonzalez

      sheetfar <sheetfar@...> wrote:
      I have a 1986 528e with a manual transmission.

      Recently, the following things have started to malfunction:

      * Speedometer doesn't work.

      * White-needle vacuum gage (located just below tach) doesn't work.

      * On Board Computer OBC works except for the fuel consumption &
      driving speed (MPG & MPH buttons).

      After driving the car for 20 minutes or so, the vacuum gage starts
      cycling on/off every 2 seconds. Eventually, the speedometer might
      work after the vac gage starts working properly.

      I replaced the expansion valve on the A/C evaporator last month.
      However, everything (all instruments were checked) worked fine after
      that.

      The most recent work was done several days ago on the rear axle
      portion of the car. If the differential transducer has a bad
      connection or has malfunctioned, could it cause any of the
      speedo/vac gage/OBC problems?



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      Message: 5
      Date: Mon, 14 Jun 2004 15:39:29 -0700 (PDT)
      From: Gerald Paul <gepaul111@...>
      Subject: Re: a/c starts out cold, then heats up

      Don't forget about maybe needing to add oil with your
      freon charge.
      --- Ron Kall <ronjkall@...> wrote:
      > A/C problem - you did not mention how old the freon
      > was? this car is R12. some not so good shops have
      > been
      > know to put R134a into these R12 systems instead. i
      > watched my guy dump 3 lbs. into mine in a shop in LA
      > and I made sure it was R12. Good work and cold as
      > ice.
      > older systems get looser and leak. belt slippage on
      > the compressor pump as the engine heats up? a/c can
      > cease to be cool if airflow goes down - stuck in
      > traffic or stopped, but mine would always get colder
      > as i went longer and faster. good luck.
      >
      > Ron Kall
      >
      > 1986 528e
      > 1985 535i
      >
      > --- sheetfar <sheetfar@...> wrote:
      > > I have a 1986 528e.
      > >
      > > What would cause the air conditioning to work fine
      > > for about 15
      > > minutes or so, then start heating up slowly?
      > >
      > > This occurs under the following conditions:
      > > * Air vents closed (no outside air leaking in).
      > > * Temp switch set to coldest (rotated CCW).
      > > * A/C fan speed set to medium or high (2 or 3).
      > > * Outside temp above 90 deg F. (It doesn't seem to
      > > act up until the
      > > outside temp is hot).
      > > * Inside air vent (vent above radio) temp starts
      > out
      > > at 42 deg F,
      > > then slowly works its way up to maybe 55 deg F.
      > >
      > > What I did so far:
      > > * Replaced the expansion valve on the evaporator.
      > >
      > > The low & high side pressure readings seem ok (20
      > or
      > > so psi low
      > > side, and 225 high side. The compressor seems ok,
      > > since it cycles
      > > off at around 335 psi when the engine revs up. All
      > > the gage readings
      > > appear to be normal.
      > >
      > > The heater control valve is working fine.
      > >
      > > I heard that the evaporator temp sensor on the
      > > earlier models could
      > > cause icing under certain conditions (Bentley).
      > One
      > > parts supplier
      > > mentioned the possibility of a bad temp regulator.
      > >
      > > Any thoughts?
      > >
      > >
      >
      >
      >
      >
      >
      > __________________________________
      > Do you Yahoo!?
      > Friends. Fun. Try the all-new Yahoo! Messenger.
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      >





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      Message: 6
      Date: Mon, 14 Jun 2004 22:48:12 -0000
      From: "gepaul111" <gepaul111@...>
      Subject: Where is it?

      I have an '86 535i. I am trying to locate the 25 amp power window
      circuit breaker. I am reading my Bentley manual, section 22-40. The
      schematic is clear enough, found the relay, of course fuse #6, but it
      doesn't tell me where the circuit breaker is located.
      Thanks,
      Jerry



      ________________________________________________________________________
      ________________________________________________________________________

      Message: 7
      Date: Mon, 14 Jun 2004 19:11:07 -0500
      From: ken@...
      Subject: RE: obc/speedo don't work

      Here is the link to dashusa.com best rebuilder of BMW dashes I have found.
      Send him the entire cluster and he can fix. I spent several hundred dollars
      and a lot of time screwing around before I found him and none of the other
      fixes worked.



      He was good and fast and it worked when he was done



      http://www.dashusa.com/euro_imports.htm







      Kenneth. H. Holyoak

      Information + Insight = Profit

      POB 68633

      Indianapolis, IN 46268-0633



      ken@...

      317-253-7000



      -----Original Message-----
      From: sheetfar [mailto:sheetfar@...]
      Sent: Monday, June 14, 2004 2:43 PM
      To: bmwe28@...
      Subject: [bmw e28] obc/speedo don't work



      I have a 1986 528e with a manual transmission.

      Recently, the following things have started to malfunction:

      * Speedometer doesn't work.

      * White-needle vacuum gage (located just below tach) doesn't work.

      * On Board Computer OBC works except for the fuel consumption &
      driving speed (MPG & MPH buttons).

      After driving the car for 20 minutes or so, the vacuum gage starts
      cycling on/off every 2 seconds. Eventually, the speedometer might
      work after the vac gage starts working properly.

      I replaced the expansion valve on the A/C evaporator last month.
      However, everything (all instruments were checked) worked fine after
      that.

      The most recent work was done several days ago on the rear axle
      portion of the car. If the differential transducer has a bad
      connection or has malfunctioned, could it cause any of the
      speedo/vac gage/OBC problems?



      To unsubscribe from this group, send an email to:
      bmwe28-unsubscribe@...








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      ________________________________________________________________________
      ________________________________________________________________________

      Message: 8
      Date: Mon, 14 Jun 2004 19:13:24 -0500
      From: ken@...
      Subject: Door Lock

      The door lock cylinder fell out of the drivers door. Inside the door was a
      very small spring and something that looks like it could have attached to
      the cylinder.



      Any idea where I can find another lock set and have it work with the
      original key?



      Kenneth. H. Holyoak

      Information + Insight = Profit

      POB 68633

      Indianapolis, IN 46268-0633



      ken@...

      317-253-7000







      [Non-text portions of this message have been removed]



      ________________________________________________________________________
      ________________________________________________________________________

      Message: 9
      Date: Mon, 14 Jun 2004 19:19:52 -0500
      From: ken@...
      Subject: RE: a/c starts out cold, then heats up

      Just went through this today. Found AC to work sometimes and not work at
      other times.



      The refrigerant has been R12 with 134 added along the way. Then sealed up
      with silicone to stop a leaky valve.



      Local AC man did great job converting the old R12 to a new 134 system and
      cost $150 including parts. Done inn two hours.



      Kenneth. H. Holyoak

      Information + Insight = Profit

      POB 68633

      Indianapolis, IN 46268-0633



      ken@...

      317-253-7000



      -----Original Message-----
      From: Ron Kall [mailto:ronjkall@...]
      Sent: Monday, June 14, 2004 3:31 PM
      To: bmwe28@...
      Subject: Re: [bmw e28] a/c starts out cold, then heats up



      A/C problem - you did not mention how old the freon
      was? this car is R12. some not so good shops have been
      know to put R134a into these R12 systems instead. i
      watched my guy dump 3 lbs. into mine in a shop in LA
      and I made sure it was R12. Good work and cold as ice.
      older systems get looser and leak. belt slippage on
      the compressor pump as the engine heats up? a/c can
      cease to be cool if airflow goes down - stuck in
      traffic or stopped, but mine would always get colder
      as i went longer and faster. good luck.

      Ron Kall

      1986 528e
      1985 535i

      --- sheetfar <sheetfar@...> wrote:
      > I have a 1986 528e.
      >
      > What would cause the air conditioning to work fine
      > for about 15
      > minutes or so, then start heating up slowly?
      >
      > This occurs under the following conditions:
      > * Air vents closed (no outside air leaking in).
      > * Temp switch set to coldest (rotated CCW).
      > * A/C fan speed set to medium or high (2 or 3).
      > * Outside temp above 90 deg F. (It doesn't seem to
      > act up until the
      > outside temp is hot).
      > * Inside air vent (vent above radio) temp starts out
      > at 42 deg F,
      > then slowly works its way up to maybe 55 deg F.
      >
      > What I did so far:
      > * Replaced the expansion valve on the evaporator.
      >
      > The low & high side pressure readings seem ok (20 or
      > so psi low
      > side, and 225 high side. The compressor seems ok,
      > since it cycles
      > off at around 335 psi when the engine revs up. All
      > the gage readings
      > appear to be normal.
      >
      > The heater control valve is working fine.
      >
      > I heard that the evaporator temp sensor on the
      > earlier models could
      > cause icing under certain conditions (Bentley). One
      > parts supplier
      > mentioned the possibility of a bad temp regulator.
      >
      > Any thoughts?
      >
      >





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      ________________________________________________________________________
      ________________________________________________________________________

      Message: 10
      Date: Mon, 14 Jun 2004 20:19:54 -0500
      From: "john Gieringer" <jcgieri@...>
      Subject: RE: Where is it?

      I did a google search, trying to find a picture... I didn't find a picture,
      but the paragraph below is a good description of where this circuit breaker
      is located on a few different models. Attached is a scan of the page in my
      owner's manual for an '85 535i - it's just to the right of the steering
      column on the lower portion of the dash.

      They were either on the dash or the center console it looks like a botton
      blank but serves as a circuit breaker. When it is tripped it will pop out
      and have red around the circumfirence. My buddy has a 92 E36 that has it on
      the center console just forward of the passenger window control. My E30 has
      it on the dash just above the Heater control next to rear defroster. Yet
      another friend has a later model E36 not sure of the year and it does not
      have the button. Check your fuses. Then pop the window switch out and see if
      it is getting power.

      John
      '85 535i

      -----Original Message-----
      From: gepaul111 [mailto:gepaul111@...]
      Sent: Monday, June 14, 2004 5:48 PM
      To: bmwe28@...
      Subject: [bmw e28] Where is it?

      I have an '86 535i. I am trying to locate the 25 amp power window circuit
      breaker. I am reading my Bentley manual, section 22-40. The schematic is
      clear enough, found the relay, of course fuse #6, but it doesn't tell me
      where the circuit breaker is located.
      Thanks,
      Jerry



      To unsubscribe from this group, send an email to:
      bmwe28-unsubscribe@...


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      [Non-text portions of this message have been removed]



      ________________________________________________________________________
      ________________________________________________________________________

      Message: 11
      Date: Mon, 14 Jun 2004 18:55:31 -0700
      From: steve <s.a@...>
      Subject: Re: obc/speedo don't work

      Try replacing the SIL batteries in the guage cluster. I have done several
      times myself. These rechargeable batteries die after awhile requiring new
      ones to be soldered in. As an aircraft engineer by trade, I troubleshoot and
      repair all day long and I like to repair audio/electronic equipment in my
      spare time. I will replace them for $70us (including parts,supplies, and
      operational test-drive in my own e28) plus shipping. Not very hard to do,
      but extremely easy to screw up-$$$$! If you're not sure, Don't Do It!
      Good Luck
      Steve from BC
      1987 535i
      ----- Original Message -----
      From: <ken@...>
      To: <bmwe28@...>
      Sent: Monday, June 14, 2004 5:11 PM
      Subject: RE: [bmw e28] obc/speedo don't work


      > Here is the link to dashusa.com best rebuilder of BMW dashes I have found.
      > Send him the entire cluster and he can fix. I spent several hundred
      dollars
      > and a lot of time screwing around before I found him and none of the other
      > fixes worked.
      >
      >
      >
      > He was good and fast and it worked when he was done
      >
      >
      >
      > http://www.dashusa.com/euro_imports.htm
      >
      >
      >
      >
      >
      >
      >
      > Kenneth. H. Holyoak
      >
      > Information + Insight = Profit
      >
      > POB 68633
      >
      > Indianapolis, IN 46268-0633
      >
      >
      >
      > ken@...
      >
      > 317-253-7000
      >
      >
      >
      > -----Original Message-----
      > From: sheetfar [mailto:sheetfar@...]
      > Sent: Monday, June 14, 2004 2:43 PM
      > To: bmwe28@...
      > Subject: [bmw e28] obc/speedo don't work
      >
      >
      >
      > I have a 1986 528e with a manual transmission.
      >
      > Recently, the following things have started to malfunction:
      >
      > * Speedometer doesn't work.
      >
      > * White-needle vacuum gage (located just below tach) doesn't work.
      >
      > * On Board Computer OBC works except for the fuel consumption &
      > driving speed (MPG & MPH buttons).
      >
      > After driving the car for 20 minutes or so, the vacuum gage starts
      > cycling on/off every 2 seconds. Eventually, the speedometer might
      > work after the vac gage starts working properly.
      >
      > I replaced the expansion valve on the A/C evaporator last month.
      > However, everything (all instruments were checked) worked fine after
      > that.
      >
      > The most recent work was done several days ago on the rear axle
      > portion of the car. If the differential transducer has a bad
      > connection or has malfunctioned, could it cause any of the
      > speedo/vac gage/OBC problems?
      >
      >
      >
      > To unsubscribe from this group, send an email to:
      > bmwe28-unsubscribe@...
      >
      >
      >
      >
      >
      >
      >
      >
      > Yahoo! Groups Sponsor
      >
      >
      >
      >
      > _____
      >
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      >
      > * To visit your group on the web, go to:
      > http://uk.groups.yahoo.com/group/bmwe28/
      >
      >
      > * To unsubscribe from this group, send an email to:
      > bmwe28-unsubscribe@...
      > <mailto:bmwe28-unsubscribe@...?subject=Unsubscribe>
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      > <http://uk.docs.yahoo.com/info/terms.html> of Service.
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      >
      >
      > [Non-text portions of this message have been removed]
      >
      >
      >
      > To unsubscribe from this group, send an email to:
      > bmwe28-unsubscribe@...
      >
      >
      > Yahoo! Groups Links
      >
      >
      >
      >
      >



      ________________________________________________________________________
      ________________________________________________________________________

      Message: 12
      Date: Tue, 15 Jun 2004 09:37:44 +0100 (BST)
      From: Paul Sharp <beemerbat@...>
      Subject: Re: obc/speedo don't work

      Hi,

      Definately check out the speed transmitter on the rear
      differential as it will affect the speedometer and
      ecometer guages. I had an 86 528i with the same fault
      and changed the speed transmitter in the diff and
      fault cleared. Hope that helps you.

      Paul Sharp,

      Aylsham, Norfolk

      --- sheetfar <sheetfar@...> wrote: > I
      have a 1986 528e with a manual transmission.
      >
      > Recently, the following things have started to
      > malfunction:
      >
      > * Speedometer doesn't work.
      >
      > * White-needle vacuum gage (located just below tach)
      > doesn't work.
      >
      > * On Board Computer OBC works except for the fuel
      > consumption &
      > driving speed (MPG & MPH buttons).
      >
      > After driving the car for 20 minutes or so, the
      > vacuum gage starts
      > cycling on/off every 2 seconds. Eventually, the
      > speedometer might
      > work after the vac gage starts working properly.
      >
      > I replaced the expansion valve on the A/C evaporator
      > last month.
      > However, everything (all instruments were checked)
      > worked fine after
      > that.
      >
      > The most recent work was done several days ago on
      > the rear axle
      > portion of the car. If the differential transducer
      > has a bad
      > connection or has malfunctioned, could it cause any
      > of the
      > speedo/vac gage/OBC problems?
      >
      >
      >
      > To unsubscribe from this group, send an email to:
      > bmwe28-unsubscribe@...
      >
      >
      > Yahoo! Groups Links
      >
      >
      > bmwe28-unsubscribe@...
      >
      >
      >
      >





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    • sheetfar
      Stuart, I have since fixed the problem, as mentioned in a previous post. (Also, I might add that the cruise control didn t work, either.) Thanks for the input.
      Message 2 of 2 , Jun 15, 2004
        Stuart,

        I have since fixed the problem, as mentioned in a previous post.
        (Also, I might add that the cruise control didn't work, either.)

        Thanks for the input. I had forgotten that they use the same
        electronic sensing devices in cars that are used in robotics and
        conveyor systems to locate the position of an object. Your mention
        of the Hall-Effect brought that back to mind. Perhaps the
        word "transducer" doesn't apply here. Maybe "proximity switch" does.
        Thank you for the correction and help.

        It is nice to know that people who have worked with various
        electronic devices and industries use this newsgroup.

        -Russ

        --- In bmwe28@..., "Stuart Logan" <stuartlogan@e...>
        wrote:
        > The Speedo is electronic in these cars, so any work to the rear
        > axle, - specifically the 'transducer' as you call it, would be
        > the direct cause of these issues.
        >
        > Also, the Fuel economy gauge is NOT a Vacuum gauge of any sort.
        > It is a relatively direct display from the Engine FI Computer
        > showing fuel delivery rate .vs. speed (from) the 'tempo' signal
        > generated by the hall effect unit in the rear axle (the same
        > unit that supplies the Speedo, OBC, and Cruise Control).
        >
        > Stuart Logan
        > '83 528e
        > '84 528e
        > '85 535i
        > '82 733i
        >
        > -----Original Message-----
        >
        > Message: 1
        > Date: Mon, 14 Jun 2004 19:42:44 -0000
        > From: "sheetfar" <sheetfar@w...>
        > Subject: obc/speedo don't work
        >
        > I have a 1986 528e with a manual transmission.
        >
        > Recently, the following things have started to malfunction:
        >
        > * Speedometer doesn't work.
        >
        > * White-needle vacuum gage (located just below tach) doesn't work.
        >
        > * On Board Computer OBC works except for the fuel consumption &
        > driving speed (MPG & MPH buttons).
        >
        > After driving the car for 20 minutes or so, the vacuum gage starts
        > cycling on/off every 2 seconds. Eventually, the speedometer might
        > work after the vac gage starts working properly.
        >
        > I replaced the expansion valve on the A/C evaporator last month.
        > However, everything (all instruments were checked) worked fine
        > after that.
        >
        > The most recent work was done several days ago on the rear axle
        > portion of the car. If the differential transducer has a bad
        > connection or has malfunctioned, could it cause any of the
        > speedo/vac gage/OBC problems?
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