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RE:RE: Intermittent Speedo

>From: "Dewey M. Sasser" <dewey=C9newvision.com>
>Date: Tue, 24 Sep 96 15:45:04 -0600
>Subject: Re: Intermittent Speedo
>
>- -----BEGIN PGP SIGNED MESSAGE-----
>
>    Ian> Help!  The VDO speedometer in my '84 318 (150Mm) has begun to
>    Ian> fail intermittently.
>
>I'll tell you the problem with my '86 325es.  If it helps, all the
>better.
>
>Gauges have staring going on my dash.  The "Inspection" light was first
>with a constant on.

This is a sure sign of dead SI board batteries.  All the green lights on  =20
all of the time is another sign.

>When I bought the car (1.08 years ago) during the pre-purchase
>inspection my mechanic did the temp gauge started going a bit nuts, as
>well.  Lately my fuel gauge has.  This is an intermittent problem.  I
>have not noticed a correlation to temperature, and it has not affected
>any other instruments.

Those problems you mention are most probably related to bad ground  =20
connections.  At the rear of the instrument cluster is a small nut and  =20
washer for each of the fuel and temp gauges that gets corroded and must  =20
be cleaned and re-tightened.

>The problem is the BMW put 2 NiCad batteries on the back of the
>instrument panel to help with current drain, and after 10 years those
>batteries have gone bad.  BMW does not sell the part (they sell the
>whole panel at $400) but there are 3rd parties who do.  A kit is $20
>and about 1 hour to put in.  They old ones have to be desoldered from
>the panel and the new ones soldered on.

While this may seem to be the problem with the gauges, I think the  =20
signals for the gauges are sent to the gauges first and then to the SI  =20
board so that in case the SI board fails, the gauge still operates  =20
properly. However, it is a great idea to replace the batteries, please  =20
check out the information at the E30 repair pages at:
http://cbsgi1.bu.edu/~bmw/repair.html for a couple suggestions on  =20
replacing the batteries.

I have also created a intermittent speedo unit fix page which will be  =20
added there as soon as I can put the finishing touches on it.

>I'm going to do it after I finished replacing the head gasket in my
>wife's Camry.
>
Good luck with that !:)


Regards,
Jeff
'84 325e  ( speedo now works )

*******************************************
    Jeff Schnellinger (jms@domain.elided)   =20
             Project Engineer         =20
    Kistler Instrument Corporation, USA    =20

*******************************************