No Power to AC Compressor on 85 442

85Cutty442

Not-quite-so-new-guy
May 1, 2016
19
1
3
#1
Hey all
I’ve been looking for my problem in the search menu, I’m not seeing my problem, if this has been answered and I missed it, I apologize.

Here’s my issue.

Compressor won’t engage,
I noticed it wasn’t working, so I traced wires and found the wires coming from the compressor had been melted, I blame myself because they ran along the intake, so no big deal, I cut away the damaged wires, replaced with new, I have continuity between compressor and plug. Fuse was blown, so I replaced it.

Figured I’m all good now as it worked fine before.

Still nothing, so I thought maybe the relay in the engine bay by the heater, replaced it with new one,
Still nothing

So I guess well I’ll jump the pressure switch to see how much Freon is in the system, jumping switch doesn’t force compressor to engage,

So I vacuum down System, and proceed to refill it, gets to half a can won’t take anymore,

Checked to see if I have power at the compressor plug, I do not, only ground

So I’m thinking is there something behind the glove compartment. I see relays, but have no idea if they are for the AC.

The AC fuse in the fuse box is good, blower fan works,

I’m completely lost, I don’t know if I’m missing something obvious from being tired.

So I ask for any and all help to getting this right again

Car is a 85 Cutlass 442

Thank you guys
 

Ribbedroof

Royal Smart Person
Jan 4, 2009
2,032
645
113
Wellston, OK
#2
With key on and HVAC set to any of the following..Defrost,Max,Norm,Bi-level check for power at the light green wire where it connects to the cycling switch. If no power there, check for open in light green wire between HVAC connector and cycle switch connector. If all the above checks out, check the mode selector switch terminal where the light green wire attaches to it on the HVAC head

If you have power there, check for open in dark green wire from cycle switch to compressor

Also check that the ground on the compressor harness is good

You could reverse the order for ease of diagnosis/accessability, since the HVAC head can be a PITA on some cars
 
Last edited:

85Cutty442

Not-quite-so-new-guy
May 1, 2016
19
1
3
#3
OK
I traced the light green wire from the low pressure switch to behind the glove compartment to a plug.
I have continuity between switch and the plug.
I have no power.
I pulled controller out a lil and looked at wires behind it.
Look ok.
I put controller on AC max, key on .
No power from controller to plug behind glove compartment.
 

Attachments

85Cutty442

Not-quite-so-new-guy
May 1, 2016
19
1
3
#4
OK
I traced the light green wire from the low pressure switch to behind the glove compartment to a plug.
I have continuity between switch and the plug.
I have no power.
I pulled controller out a lil and looked at wires behind it.
Look ok.
I put controller on AC max, key on .
No power from controller to plug behind glove compartment.
 

Attachments

85Cutty442

Not-quite-so-new-guy
May 1, 2016
19
1
3
#6
Boy I screwed that all up.
The first pic is the bypass plug I believe it’s called, I have power there, I believe that comes from the fuse box under the dash.

If the controller is supposed to send power to the low pressure switch through that light green wire.
Then that would be my issue, since I have no power.
 

olds307 and 403

Comic Book Super Hero
Oct 14, 2008
3,286
706
113
Melville,Saskatchewan
#7
There should be relay tied into that light green wire. I actually manually bypassed mine with a toggle switch. Same thing, burnt and hacked wires. I find the electrical garbage in these cars.
 

85Cutty442

Not-quite-so-new-guy
May 1, 2016
19
1
3
#8
There should be relay tied into that light green wire. I actually manually bypassed mine with a toggle switch. Same thing, burnt and hacked wires. I find the electrical garbage in these cars.
The light green wire is see is coming directly out of the controller into a plug behind glov3 compartment, then travels up straight to low pressure switch plug.

Is that supposed to have power when selecting AC from the controller?

If yes, I need a controller, if no then which wire sends power out please?
 

Texas82GP

Comic Book Super Hero
Supporting Member
Apr 3, 2015
4,233
3,355
113
Spring, Texas
#9
This might help...
FourSeasonAirConditioner.jpg
 

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