Like many other 6er owners, I've been putting up with the service lights (SI lights) that are controlled by the SI board located in the dash cluster. The nicad batteries soldered to this board eventually fail with age and you can't re-set your service indicator ..... so the lights just stay on all the time. This is annoying enough, but my temperature gauge also began to act erraticly. It would seem to be working fine, then the needle would drop to dead cold ..... sometimes coming back after a while, sometimes not. This gave me quite a scare initially. Fortunately I also have an IR temp gun that I was able to use to verify that the engine was not running hot. Checking the temps this way is not convenient at all, and really does not provide the constant assurance that I feel is needed. So last week I decided to pull the gauge cluster and attempt to get the temperature gauge working correctly ..... plus disable the SI lights.
If you would like to try this yourself, there are excellent instructions on removing your instrument cluster here:
http://www.z3bimmer.com/OffTopic/E24Bimmer//OdoGear/
Once I got my cluster out, I carefully took it apart and removed the SI board. I had read that if the SI board was not damaged by corrosion seeping from the dead nicad batteries, that they could simply be removed and everything would work fine (except the service lights would just stay on). I decided that if that was the case I could live with that ..... as long as my temperature gauge was working correctly. Here is what my SI board looked like:
front side
By
r_e_l at 2012-04-04
back side
By
r_e_l at 2012-04-04
The nicad batteries were not leaking and after careful inspection I could see no damage to the circuit board. So I carefully cut the batteries loose where they were soldered to the circuit board with my Dremel tool.
Here is the SI board less batteries.
By
r_e_l at 2012-04-04
Everything looked really good so I decided to reinstall the SI board (less batteries) and see how things worked. Well, I buttoned everything back up
hit the switch and the results were not good. The gas gauge went to empty, and the temp gauge started bouncing around. This was a lot of work as the connections on the back of the instrument cluster are really hard to reach when removing them ..... and even harder to get to when reinstalling the cluster. It was Thursday evening, and I was disappointed and tired .... so I just turned it off and shut the garage door.
Later that evening I did some research on replacement SI boards and found the ProgRama site which describes their batteryless replacement SI board for 6ers thru 1985. This seemed to be a good choice to me, so I ordered one.
The ProgRama batteryless SI board arrived Tuesday afternoon and I was able ti get it installed last night (things went a little faster on my second removal and reinstall of the instrument cluster)
Here is what the ProgRama batteryless SI board looks like .... quite a bit simpler than the one it replaces .... and fits perfectly.
By
r_e_l at 2012-04-04
I'm happy to report that I fired up Crystal this morning and took her for a short drive. All the gauges, including the SI lights are now working perfectly. I did have to do the work twice, but I'm happy with the results ..... and I also swapped out the 3V cluster lights for 5V ones on the 2nd time around, so now I have brighter dash lights as well
If you are interested in one of these ProgRama batteryless SI boards, I got mine here:
http://programainc.com/product_detail.a ... 1139427001