alt/battery light malfunction, no other problem

[dlb]

when i turn the key to 'on,' the charge light (the one with the battery icon) comes on for just a split second and then goes out. all the other warning lights stay lit until the engine is started. i haven't measured any voltages yet but i've been driving the car a fair amount and the alternator and battery both seem to be working fine so i'm not too sure where to start looking. has anyone else had a similar experience?

[TURTCEL]

I have not had this happen with my Terc, light stays on with the rest until started on mine...just checked. But...I did own a VW Westy '83 1/2 (2.1L water-cooled/swap) that had an issue with the fuel gauge not working. I know it is two totally different things but the point is that it turned out to be a bad diode in the back of the gauge...replaced and fixed. The mechanic checked it with his multi-meter and that is how he found the prob.

Sounds like you may be in to an electrical Sherlock Holmes adventure...never super fun. Good luck.

Peace

[irowiki]

David, if you don't have one of these, I've found them very handy!
http://www.etoolscity.com/tooluxe-led-c ... MwodGREAWA


Do you have another hood to test with?

[dlb]

...it turned out to be a bad diode in the back of the gauge...

hmmm

Do you have another hood to test with?

ahhhhh. i didn't, but i might be able to. i think c_j has a spare i could try. good thinking!

[irowiki]

I got to thinking, is it really the gauge when all that stuff goes through the hood?

I would not not have known this before buying the wagon

[dlb]

tried another hood, no change.

[irowiki]

I need to look at a wiring diagram, looks like a nice puzzle.

[marlinh]

Maybe this will help. Mind you, if you tried another hood it can't be the diode.



The light seems to get it's ground from the choke stat.

[dlb]

thanks for those, marlene. i had looked at some wiring and saw that the auto choke was related so i checked the resistance of it and it was within spec (22 ohms), and seems to work fine (choke closed when cold, opens as it warms). not sure how else to test it.

the search continues!

[dlb]

today i swapped the alt/battery warning light bulb with a known good one, problem remains. then i checked for clean contacts on all the alternator connections, all were good. then i noticed that a small brown wire with a black stripe comes out of the large bundle of wires going to the alternator. it plugs into two larger wires, probably 16 gauge. one of the big wires is also brown with a black stripe, the other is brown with a yellow stripe. as far as i can tell, both of these big wires are grounds that connect to the block. the two brown/black wires connect at the plug but the brown/yellow doesn't wind up connecting to anything. can someone take a look at their terc and tell me if they have a wire that connects to the big brown/yellow, and where that wire goes to? i've looked in the wiring section of the manual and can't see any brown wires in the alternator system so maybe they belong to something else, i dunno.

here's a pic of the wires i'm wondering about.

[KZ750]

Pictured is your brown wire with yellow band meeting into the main, black with yellow band, ground wire of the car. (what i'm holding) The other end of this black and yellow ground wire connect straight up to the negative terminal on your battery. Now any chance you can show me the proper ground location for this end of the wire on the block? Haha I'm in a pickle too.
Not sure but, I think all OBD1 and older cars have the lights hang before start up. My OBD1 system Jeep does. I think it's a problem when the lights continue to stay on after start up..? not sure though. You definitely should get your brown with yellow band wire grounded though. Hope this helps and sorry for the bump .

[KZ750]

also the location of the brown with black stripe wire?

[KZ750]

......I think I got ahead of myself. your system looks different than mine.