AC fuse power source

[SUMMIT CRUISERS]

Got a 92 and today the AC quit working. Compressor works if I apply 12 volts to it and it cools fine. Checked the 10A fuse and I have no power to the right (inlet side) of the fuse. I checked power on the two fusable links and all other fuses under the hood and inside with no problems found. ?Where does the AC fuse get it's power source? Mine is 0 volts.

 

[SUMMIT CRUISERS]

Jumped the back of the AC fuse from another power source and still no 12 volts to the compressor (with truck running, AC button depressed and fan on). Any ideas from any Air Conditioning/electrical gurus?

 

[SUMMIT CRUISERS]

BTTT

Update:

Jumped the pressure switch by drivers front head light. Still no power to AC fuse.

? Would the starter cut ac relay kill the power to the AC fuse? If so where is it?

 

[Bjohnston115]

take a look at the wiring diagram attached. Perhaps your heater relay is bad. It seems as if it feeds the AC.

 

[SUMMIT CRUISERS]

take a look at the wiring diagram attached. Perhaps your heater relay is bad. It seems as if it feeds the AC.

Thanks so Much. I jumped the sensor wiring harness that goes to the evaporator. I then got my 12 volts to the AC fuse. Tried the AC and still no power to the compressor. Any other ideas?

 

[SUMMIT CRUISERS]

BTTT,

Still no power going to compressor. Any ideas?

 

[Bjohnston115]

sorry man... i will try to trace my system tomorrow to see whats going on. I have a 92 as well so ill check all the parts. It seems as if when you jumped the evap you got power to the fuse, that tells me the sensor is bad.

 

[SUMMIT CRUISERS]

sorry man... i will try to trace my system tomorrow to see whats going on. I have a 92 as well so ill check all the parts. It seems as if when you jumped the evap you got power to the fuse, that tells me the sensor is bad.

That's what I was thinking. Now I'm just wander what else (sensors/relays) could be bad. I took out the AC amplifier and board. The board appears to be is normal and looks factory new. No burnt resistors or other.

Thanks so much for all your help,

Steve

Summit Cruisers

 

[SUMMIT CRUISERS]

Checked the AC switch and amplifier relay (on the circuit board). When AC switch is depressed with fan on, relay on board transfers 14 volts from yellow with red stripe wire to yellow with red dashes. AC switch and Amplifier relay works properly as it appears. Still no 12 volts to compressor. Ideas? Anyone?

One more, when the AC switch is depressed and the amplifier relay clicks in, the idle rpms do not increase. They previously did before this happened. So no idle air control working either.

 

[SUMMIT CRUISERS]

Fixed AC

sorry man... i will try to trace my system tomorrow to see whats going on. I have a 92 as well so ill check all the parts. It seems as if when you jumped the evap you got power to the fuse, that tells me the sensor is bad.

Thanks for you help, just figured it out. Posted up a different thread here https://forum.ih8mud.com/80-series-tech/498409-ac-help-desperately-needed.html

 

[Eagle Scout]

Resurrection of this thread - same problem

AC died when I decided to update the stereo - fan will not blow. Here's what I have done:

1. checked all fuses, both fuseboxes - replaced a square green 40 amp fuse in driver's knee area fusebox that was blown
2. replaced 3 fusible links in driver's toekick plate, 2 round 4 connectors, 1 square 5 connector.
3. replaced head unit (wanted to do that anyway as buttons were squishy and not crisp)
4. Made sure the white corrugated hose is plugged into the back of the head unit, as well as the 2 prong connector and the blue and white connectors. Used small can of compressed air cleaning lint from small temp sensor.

Only connector in that area that I have not plugged into something is the small white connector that rises from the wires to the cigar lighter blade plugs. Figured it was an accessory power plug.

Am I missing something pretty simple, or is it time to visit the mechanic? I have enough personal time and auto parts into this already...........