Help!

[andyvillen]

I have a 91 k2500 with a 6.2l and the batteries aren't charging. I have recently ( 2 weeks) put new batteries in and it started good and was charging.

If I check the output of the alt it's at 14.3 v but it's not getting to the batteries. I tried following the output cable but it goes into the firewall harness.

Does anyone know where the wire actually goes or what the problem is?

[Yukon6.2]

Hi
There should be a large wire from the alt to the battery's.
On my 96 i didn't hook it up once,i believe i had changed the motor and missed it in the final hookup.I was worried the Alt had been damaged then after a few anxious minutes i saw it laying below the battery.

Thomas

[andyvillen]

Yeah, that's the weird thing, the wire dosnt go right to the battery..... It heads down to the glow plug harness and from there I don't know.

I'm getting 14.3 at the terminal on the alt. and nothing at the batteries.

Does anyone have a wiring diagram for a 91 gmc k2500 vin c

[Yukon6.2]

Hi Andy
It may head to the starter,i don't think i'v seen one go anywhere else the starter or battery.
You could disconnect the large wire and hook up a temporary one from the alt to battery.
Thomas

[phantom309]

I think mebbe it has a fusible lnk in the line too,.
A direct line from the hot stud on the alternator to the closest battery would work the best,(.unless you are determined to keep everything factory stock

[andyvillen]

Yup, I have put a cable temporary to the battery. I have to check to see what is on the starter in the way of cables..
I'm still not very happy with the charge of the batteries with the temporary cable.
It's better than it was but if I run the plow steady it draws down the batteries,

I'm thinking if it does run to the starter I could have a bad connection on the starter, with a good alternator there is enough amperage to over come the resistance of the bad connection.
I don't have anything to really test the amperage on a altanator, I guess I'll have to buy a new alternator an try that.

[Dvldog8793]

Howdy
I have run a plow with an 89 chevy gasser. So only one battery, but I had a 170amp alternator. It never ran down the battery or even seemed to slow down with steady use. If recall...the two factory choices for Alternators of that year would be 100 or 145amp.
I would start by rewiring and cleaning EVERY connection, if you see green in the strands, eliminate/replace the entire wire if possible.
Use a light coat of copper never-sieze on all you connections, Solder splices, no crimps.
Hope this helps...