Fzj 80 air con not working

[PJ fzj80]

Hey gang, I need some help please. I went to turn the air con on the other day in my 80 series, the light on the switch went on. No air con. I checked the fuse under the dash and all good. I didn’t hear the relay kick in like normal. Is There a way to test the relay? Is there something I may be missing? I appreciate any help as auto electrics aren’t my strong point.
thanks heaps, Jamie

 

[enox]

Check to see if the clutch on the compressor engages/ disengages when you press the AC button.

I went through my AC a few months ago.
Clutch was working.
Air wasn't cold.
Replaced compressor (it was a no brainier, few hundred bucks and I have no clue how old mine was)
Replaced the high pressure switch.
Replaced the evap valve.
Blows cold AF

You can test the high pressure switch with a jumper (search it here)

As far as specifically testing the relay, im not sure but maybe someone else has a write up here.

I did a few extensive searches here and I came across a few write ups when I looked...hope that helps.

AC bugs are a pita.

 

[flintknapper]

It's 'usually' best to check the A/C from the Compressor backwards toward the dash, not the other way around.

I like to start by looking to see IF the compressor clutch is engaged (engine running, AC on). IF it isn't then I will run 12volts directly to the compressor clutch to determine whether or not it is capable of operating. IF it doesn't engage (engine off, 12volts directly to clutch) then it is likely your problem.

IF it does engage then the next thing you'll want to do is check the 'static' pressure of the system (refrigerant charge). You will need a set of manifold gauges to do that. Your system has a binary switch (high/low pressure switch) that will not allow the compressor to engage if the pressure is either too high or low. By checking the 'static pressure' (engine off, AC off) you can see if there is enough system pressure (roughly 35-50 psi) to let the unit operate.

IF there is enough pressure then you'll want to move to the pressure switch itself and test it (check connections and bypass if necessary). IF the pressure switch proves to be good THEN start looking at electrical components (fuses, relays, wiring, switches, etc).

Good luck Sir. A/C issues are always fun.

 

[Malleus]

^this

 

[JoeW]

Having recently gotten my A/C up to snuff, my experience and diagnosis was pretty much spot on with @flintknapper. Although, with the old rigs, it may be a multi step process, so be prepared for that.

I had just gotten the car running and was seeing what worked and what didn't. I'd push the button but noticed the clutch on the compressor never engaged. I pushed on the high side service port for a split second with a pocket screwdriver and noticed no refrigerant came out. I recharged and added some dye and low and behold the clutch engaged and I had cold air. I ran it like that for a week and when I was doing some other projects, noticed the compressor was literally glowing green from every seal pretty much! Swapped in new Denso compressor, receiver drier and expansion valve (should have done an evaporator while i was in there) and again my AC was blowing cold as ice. During another inspection I noticed dye leaking from the middle of the condenser where a pinhole leak was. I replaced that with another Denso part from RockAuto and now it would appear that my AC is leak free. I never touched the control module or anything like that. It was all hard parts under the hood/ dash.

 

[alia176]

Hey gang, I need some help please. I went to turn the air con on the other day in my 80 series, the light on the switch went on. No air con. I checked the fuse under the dash and all good. I didn’t hear the relay kick in like normal. Is There a way to test the relay? Is there something I may be missing? I appreciate any help as auto electrics aren’t my strong point.
thanks heaps, Jamie

First and foremost, see if there's enough freon in the system by using a manifold pressure gauge or one of those cans of freon with a hose&gauge already attached to it. If the system is low then it won't run which means you have a leak. You could simply add freon if it's needed and see if the comp turns on. If you have enough freon in the system, then start the troubleshooting steps as mentioned above.