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73-87 Chevy _ GMC Trucks => Body, Glass & Paint => Topic started by: 1976Scottsdale on February 23, 2006, 01:44:00 pm

Title: Wiring question
Post by: 1976Scottsdale on February 23, 2006, 01:44:00 pm
I am finishing up my 78 K-10 tomorrow night.  Before the front wrap goes on, I have one question about the wiring.  On my truck, someon had tore up the wiring really bad... it was a fire trap.  Anyway, the red wire to the starter and the red wire to the alternator were joined by a little metal home made looking thing and had about 3" of bare wire hanging out, is this correct or incorrect?

Title: Wiring question
Post by: Lt.Del on February 23, 2006, 02:31:00 pm
That can't be good.  There is no way that is correct.  On my 79, I'll see what the red alt. wire goes to or/and the red starter wire.  I'll post again then.

SgtDel

Title: Re: Wiring question
Post by: 1976Scottsdale on February 23, 2006, 05:44:00 pm
That is what I thought.  I will also state that the truck would never hold above 13 volts at idle either.  I have had seven of them and every other one has always had at least 14-15 at idle.  I did away with the coupler thing and just joined the wires to the ones that they belonged to.

Title: Re: Wiring question
Post by: Lt.Del on February 23, 2006, 10:38:00 pm
Well, here is a pic from the alternator.  The wires go into the wire harness and towards the firewall.  I can follow it up to where it joins the main wire harness undere the hood on the firewall.  Where it goes from there, who knows?






The wire from the battery goes directly to the starter (starter cable).  There are some wires on the solenoid that, too, goes into the wire harness.  

Without referring to a wire diagram, I am afraid that is all I can offer.

SgtDel

Title: Re: Wiring question
Post by: 1976Scottsdale on February 24, 2006, 10:18:00 am
No big deal, thanks for the help anyway.  Just to be safe, I marked the wires in the harness and left enough room to get to it later if I have to change it back.

Title: Wiring question
Post by: Lt.Del on February 24, 2006, 11:15:00 am
You should still be getting over 14 volts directly from your alternator.  PUt a volt meter directly on the red wire on the back (not side)of your alt, ground the black lead of meter, and read the volts. That'll tell you if your alt. is good or not.

SgtDel

Title: fixed it.
Post by: 1976Scottsdale on February 27, 2006, 05:55:00 am
As it turns out, whatever was connecting those wires needed to be there.  It actually ended up being the red field wire on the alternator and the red alternator wire that bolts to the alternator.  Not fun to remove new wire loom from the whole engine bay at 2:00AM jut to find that the patch was in the loom going to the alternator.  Oh well, I fired it at 2:30.  Ran well.  Holds 65 psi oil pressure at 2000RPM's and at a hot in gear idle I get 50psi.  Motor has 23 miles and 4 hours run time on it.  It scared me a little when it had run for about 45 seconds and then pumped up all 8 pass side lifters at once.  It sounded like it was locking up.  But it wasn't.