I've got an 87 gl with a low voltage problem. At idle with the rear defogger, ac, and bright headlights on the voltmeter on the dash(analog) reads 8-9 volts. Under the hood the alternator is putting out 13.8-14.0 volts measured at the alternator and the battery. The fuses are all ok and the fuses are reading about 10-11 volts. The fuse links under the hood are ok also. The battery is being charged and running the engine ok but accessories are underpowered: The windows roll up slow and not all the way, the ac fan is slow, the radio cuts out and loses its presets etc. The alternator checked out ok but I replaced it with a good one a friend had with the same results. I'm stumped - any ideas?

I would start checking, cleaning the grounds.My 84 gl has two main grounds, one body ground at the batery box and an engine ground on the engine deirectly across from the battery.Those are the only ones that I know of but somebody with more time on the subys will probably know more.

 

good luck

the feed to the fuse box has problems, my GL-10 was doing about the same thing

I ran an aux wire (14 AWG) from the fusible link to the fuse box, paralleling the main feed.

Thanx for the comment on the ground. I just pulled the engine to replace a torque converter seal. I got to thinking about what you said and remembered the huge ground to the bell housing but couldn't remember a ground to the chassis from the battery. After checking I found an 8 gauge ground wire from the radiator support to the ac bracket I overlooked. It grounds the chassis to the engine/bell housing. Problem fixed! This is a great list!

If the simptom is that the puwer is loosen or the memories became volatile allways check the ground because these older cars somtime came in contact with the problem of oxidation what causes the bad contact, and therefore all that inconvenient.

Hi!!!