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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: sscobra on June 30, 2010, 12:26:34 am

Title: A/C Wiring Question, Help Please?
Post by: sscobra on June 30, 2010, 12:26:34 am
I have an 86 C10.  I recently decided to try an get the a/c working.  However, there's a problem. When the ac is turned on, the compressor kicks on.  Great, right?  Well, here's the problem.  When I disconnect the low pressure connector from the switch the compressor keeps running.  I did rebuild the a/c compressor harness(factory one was shot) coming from the firewall connector to the compressor.  I thought I built the harness identical to the factory one.  So does anyone know where I can find an a/c wiring diagram. I checked the diagrams on this site(which are the same ones from my haynes manual) and they show nothing about the a/c wiring.  Any ideas?  Your help is appreciated. 
Title: Re: A/C Wiring Question, Help Please?
Post by: Lt.Del on June 30, 2010, 08:35:45 am
that wire should be a green wire.  You can take a volmeter and check for a closed circuit after you unplug the plastic switch connector. 

Title: Re: A/C Wiring Question, Help Please?
Post by: sscobra on June 30, 2010, 08:58:13 am
Thanks for the response.  The black connector coming from the firewall harness has 2 leads with 3 wires.  One lead has 2 wires going to the back of the connector(they are green).  This is the lead that I get power to when I turn the a/c switch on inside.  I'm not sure what the other lead is for in that connector, as I wasn't able to get power to that lead.  Also, I am getting "switched" on/off power to the low pressure switch(should mean the wiring there is fine).  The new harness has a single wire that goes from the 2lead/2wire green wire black connector to one lead on the compressor and the other lead on the compressor goes to a ground on the bracket.  I was pretty sure this is the way factory harness was done?  Thanks for any help.
Title: Re: A/C Wiring Question, Help Please?
Post by: VileZambonie on June 30, 2010, 03:52:55 pm
(http://i6.photobucket.com/albums/y228/Sabaka454/acwiring.gif)
Title: Re: A/C Wiring Question, Help Please?
Post by: VileZambonie on June 30, 2010, 03:53:42 pm
Click Here for the full size (http://i6.photobucket.com/albums/y228/Sabaka454/acwiring.gif)
Title: Re: A/C Wiring Question, Help Please?
Post by: sscobra on July 01, 2010, 09:35:44 am
Thank you sir! That's great.  So are does the dark green wire and the black ground wire combine at the compressor or am I looking at it wrong?  Thanks again for the help.
Title: Re: A/C Wiring Question, Help Please?
Post by: ccz145a on July 01, 2010, 11:10:19 am
They do not combine.  Not sure if it is drawn that way to represnt a loom or to save on drafting man-hours.
Title: Re: A/C Wiring Question, Help Please?
Post by: sscobra on July 01, 2010, 07:11:38 pm
Thanks for all the help.  I figured it out.  I was rushed when I finished the harness.  I had connected the compressor harness to the idle soleniod side of the connector.  Switched the wires around and I was getting power where and when(ie: only when the pressure switch was engaged) I need it.  Also, does anyone know where the orfice tube is located on these trucks?  Thanks again for all the help.
Title: Re: A/C Wiring Question, Help Please?
Post by: VileZambonie on July 01, 2010, 07:35:27 pm
In the dimpled line right before the evaporator (after the nut)
Title: Re: A/C Wiring Question, Help Please?
Post by: sscobra on July 06, 2010, 08:43:56 pm
I've got A/C!!  ;D  Now I feel really good about my $650 purchase.  It's nice to be able to take my son with me now when we need to take the truck.  Thanks again to everyone for all the help!