Hi Folks,

I'm having an instrument cluster issue.

Getting no charge from the alternator. I assumed it was because of the classic 940 short in the instrument cluster, and so I did the solder repair with no luck. ???

I've repaired a 940 cluster with the refloat solder trick before and it worked fine. This instrument cluster in question is low miles (86k) and the joints all seemed to resolder fine. I went over it three times and resoldered every single joint. But only getting 12v at the battery and alternator.

Also only getting a few idiot lights when turning the key on; CEL, coolant, seatbelt and SRS (for only a second).

Inspecting the circuit with a magnifying glass does not show any damage.

The alternator is known good. The battery is new.

???

I do have a lead on a working cluster to swap in. Hopefully, I'll get it and get running, but I'd love to fix the original cluster.

Any suggestions?

Thanks,
Bert

Dear Mr. Nabisco,

Hope you're well. The alternator will not start to charge: (a) if the instrument cluster bulb, that illuminates the battery symbol (for charging), has burned-out or (b) if there's a break in the thin red wire that connects the instrument cluster bulb (which supplies the "excitation voltage" to the alternator) to the alternator.

The cluster's solder joints could be completely fine. If, though, items (a) and/or (b) are not in good working order, the alternator will not charge.

The short time that the instrument cluster warning lights are "on" could also reflect a faulty ground. I believe the instrument cluster ground is beind the door-side kick panel, in the driver's footwell.

Hope this helps.

Yours faithfully,

Spook

Thanks for the added info Spook. That red wire and ground would have been my next step.

Ends up the "known good" alternator was bad. New alternator and all is good. The soldering trick was the fix.

Bert

Dear MrNabisco,

Hope you're well. If a new alternator solved the problem, then was there actually a problem with the "low-miles" cluster? Or, were there two problems: a failed alternator AND a micro-crack in an instrument cluster solder joint?

Yours faithfully,

Spook

Spook,

Yes, I had a dual failure. Bad alternator and cracked solder joints in the cluster.

Replaced the bad alternator with a "known good" one... Which was also bad. So actually I had a triple failure.

These multiple failures are always the trickiest.

Thanks again for adding info. Always good to know more.

Bert

Bert, I have a cluster from a '92 (I think-maybe '91) 740 -- took it in trade for the cluster from my "wrecked while parked" '92 940T. His speedo didn't work - you are welcome to borrow or buy it for diagnostics/repair. -- Dave

Thanks for the offer Dave.
I'm on Ohio with this car.

Just got a supposedly working cluster... About to try it.

Really curious if I could get that original cluster to work.

Bert