[Prev][Next][Index][Thread]

Re: E28 jumpy gauges

> From: Brian.Foster@domain.elided
>
> The 1985 E I just picked up had a similar problem... everytime I stepped on 
> the brake pedal, I'd get a "pop" which would cause an sporadic drop of the 
> speedometer, the check light to come on flashing, and occasionally a 
> failure of the radio.
> 
> As it turns out, the latest Tech Talk Column from Craig @ Brecht BMW (Sept 
> Fahren Affairs that's on its way) addressed this problem with one of two 
> potential culprits: drained batteries on the gauge cluster PWB or a bad 
> circuit on this same PWB. In my case, I had both. It sounds to me, that the 
> car is probably old enough that all you really need to do is have a 
> mechanic with decent PWB soldering skills check over the board, look for 
> lifted traces, and replace the battery.

Another thing you may want to check if you suffer from this problem
(occasional radio failure and speedo, especially when hitting bumps and
stepping on the brake) are the fuses.  The E28 still uses the old
style ceramic fuses, and the contacts do get dirty, loose, and corroded.
Dirty/loose fuses for the check control, speedo, radio/brake light can and
do cause symptoms such as these.  As with the 2002 and older cars, it's
not a bad idea to replace the fuses every couple of years.

Hope this helps,
Ben