Our 1991 140G (72V13881) has a weird issue that half the warning lamps on the dash are on at half brightness. Started this spring and shortly after replacing bad batteries. My first feeling was a bad ground but have messed with as many ground connections as I can find. Have also messed with the sensor connectors and the cannon plug into the panel. Odd thing was I was pulling it out of the shop for the weekend and as I was moving something tripped and all the light started flashing bright and the alarm and I just flipped the key off and back on and it went back to being half bright again. Maybe there is a common issue with this that someone knows about before I start tracing every wire. Attached are photos of how it kinda looks right now and when they are full bright doing a panel test. The 3 lights that look bright in the first photo are actually only half bright and the rest are pretty dim, just hard to capture on picture.
Couple of questions: - Have you tested the alternator output voltage..? Do you have the Electrical Schematic..? Does the Action Alarm sound and the Master Fault light come on during the self-test immediately after you turn the key on..? After the panel self-test do the lights immediately go "dimmer" or does it take some time..? I'm thinking dodgy connection somewhere, but to find it could be a Sherlock Holmes task. Maybe start by disconnecting EVERY sensor that has a feed to the EMS panel, power up, and start reconnecting the sensors one at a time until the panel goes screwy again. However to do that would require a schematic so that you know what to disconnect and where the connectors are.
Have not tested alternator, will do that now (edit have 27.5v running). The only schematics I have are in the supplemental book for the AWD, etc. Also have a parts book so trying to decipher the wiring based on parts locations as best I can looking at the parts. It immediately goes back to dim after the self-test.