Good morning!

I hope you follow the previous posters' advice and check to see if the system charging voltages are correct. If not, and the wiring to the alternator checks out ok, the problem could be the printed circuit in the dash cluster.

While I didn't have your charging problem in my '93 940, I did have a faulty gas guage and a non-working ABS warning light. Both problems were caused by tiny breaks in the printed circuit. This printed circuit is on flexible plastic and a bit too delicate for my tastes. I was able to find the tiny breaks using a digital ohmmeter ($5.00 at Harbor Freight) and a wiring diagram.

The wiring diagram is needed to find out, on the connector to the cluster, where the alternator circuit enters the printed circuit. The procedure is to connect one lead of the meter to the entry point and then visually follow the circuit trace making meter connections to points along the way. When the meter indicates a sudden high or infinite resistance, you know you have just passed the break.

In my case, there was a cracked solder joint along the path for the fuel guage and a hidden break in the circuit trace to the ABS light. Neither break was visible to the eye. The crack in the solder joint was visible with a 10X magnifier and the 'hidden break' was under a plastic tab where it was totally out of sight. I resoldered the first and soldered a bypass wire around the hidden break. Both problems have not reoccured in over a year now. Hooray!!!

Getting the dash cluster out was a bit hard since it had never been out before. The second time I pulled it, it was easier. I found how to do this using a search on this great forum. If you haven't done any circuit tracing, now would be a good time to learn. It isn't all that hard. Good luck!