Mous

'94 s-10, 2.2 L, 4 cyl. Fuel injected.
Engine gets bad mileage. Headlights and instrument lights dim sporadically. Gauges, speedo, & tach occasionally slip to lower reading also sporadically but not always in sync w/ dim lights or each other. Both are worse when the headlights are on. I'm guessing it's a ground or volt regulator, (or something). Can someone suggest an isolation test procedure?

kevinkpk

Yes, I'd say loose connection(s)

geo1

Any luck?test alternator at parts store?

Mous

it's not registered so I can't drive into town, it's also raining so I'm still considering what to do. kind of a relief to find the lights flicker, since I hadn't driven it at night. I suspect there probably are a couple of bad connections like kevinpk said. I'm suspicious of multiple problems doing the same thing though. maybe a bunch of terminal clips corroded while sitting outdoors for 5 yrs.

update 30 sept 4:00 found a piece of tinfoil stuffed in one of the fuse slots but according to the schematic on the cover that location (#5) isn't connected to anything. the volt meter shows better charging though (14 instead of 12). the fuse box might still have a ground fault, the tach needle wiggled only once when I drove it down the hill (that's an improvement).