Intermittent Charging issue - at whits end

[geezer101]

The alternator needs the battery in the system to regulate charge voltage. I would do an error code check on the ECU and see if anything comes up. Vehicles in the 90's began to have active charging regulation triggered by the ECU. I don't know if the MM fits into this category though. The biggest gremlin in an electrical system is a bad connection somewhere - usually the grounds get funky and no longer have a solid connection but you've stated that you have cleaned them all so that is a good start.

[4gCO]

The alternator needs the battery in the system to regulate charge voltage. I would do an error code check on the ECU and see if anything comes up. Vehicles in the 90's began to have active charging regulation triggered by the ECU. I don't know if the MM fits into this category though. The biggest gremlin in an electrical system is a bad connection somewhere - usually the grounds get funky and no longer have a solid connection but you've stated that you have cleaned them all so that is a good start.

I'm just popping in to let y'all know that I ordered a new ground cable, it should be here on Thursday and I'll put it in ASAP. Hoping thats the source of the issue. As far as I can tell from everything, the blue wire only goes to the dash light, not the ECU, but I would be happy to be proven wrong on that point, that would help me emmensley in diagnosis, just knowing where that wire goes and what sort of signal it is expecting.