A/C Troubleshooting (1 Viewer)

[Two Buck]

My 85 FJ60 has spent much of the last 10 years not being driven much and the A/C not used at all. I have a vague memory of it working in the past -- but that could also just be wishful thinking. In any event, it's not working now and since I'm bringing the truck back into service as a semi-DD it would make the Mrs happy and more likely to agree to throwing $$ at it if the A/C were working. The heater and blower motor work fine, and the blue A/C button lights up when I press it, but that's the extent of it.

So... Where should I start looking to figure out what is and isn't working? Can y'all give me some guidance on troubleshooting, and maybe point me toward a copy of the air conditioning FSM?

 

[Demonic92]

Page 223 Land Cruiser Toyota AC, Wiring Diagrams & Power Steering Manuals
I'm not good with A/C at all but sounds like the refrigerant has leaked out.

 

[pandasfj]

Hey 2$, try getting a set of refrigerant manifold gauges and check to see if you have pressure in your lines.

 

[Demonic92]

Maybe this will help - working on refilling the R12 refrigerant in my 91 FJ80.
RedTEK vs EnviroSafe refrigerant

 

[SteveH]

If the blue button lights up, you have some pressure in the system. Check the center vent temps with the A/C on and off with a dial probe thermometer. Hold the engine at 2000 rpm, and see if there is ANY cooling effect. If so, this means the system has some pressure (which you can verify by pressing the low side valve quickly and listening for hissing). If you have pressure, it means the system is not contaminated with air. I would then try adding 1 can of R12 to the system and seeing what happens. I have serviced 2 neglected FJ62s this way - both were sitting and very low on refrigerant, and I did not have do any grand A/C work and convert to R-134a, etc. Don't mess with what isn't broken. When I did this to my truck, the coldest center vent temp I could get was 69F on a hot day. After adding 1 can of R-12, it dropped to 44F. Like magic. Well worth whatever 1 can of R12 costs in Kalifornia.

If you don't have any parts, you can buy R12 'charge kits' on eBay for cheap. They are junky Chinese-made stuff, but will work to get one can added.

 

[DirtRoads]

Verify that it has the correct charge or pull a vacuum on the system and recharge it. If it produces cooling satisfactory to your liking, you are done and can have another beer. If not, troubleshooting can begin. It's a simple system, nothing to be afraid of.

 

[FJACS]

If you have to “break the seal” on the system so to speak, replace the receiver/dryer (mounted near the radiator). These are cheap from places like Rock Auto.

 

[Spook50]

Maybe this will help - working on refilling the R12 refrigerant in my 91 FJ80.
RedTEK vs EnviroSafe refrigerant

I've heard good things about Duracool 12a also. Once I leak check my 62's system (I think a faulty shaft seal in the compressor is the culprit for my leak) I plan on recharging with that.

 

[Bama4door]

I've got similar symptoms to the OP. AC worked fine last year, but now compressor isn't coming on and no high idle with blue button pushed. Blue AC light comes on, but compressor is not engaging. I went to add some r134 to the system yesterday and still couldn't get the compressor to come on.

Just checked the 10A fuse behind the dash panel and it was blown. Replaced it and still no compressor kicking on. Any ideas?

 

[morganism]

If you just want to run it to test it, without having to pull a vacuum on the system, you can run it on propane.

And before the yelling starts, ALL the 134 replacements are flammable.

If you can get ahold of a camp stove with a flex line, you can usually rig up a converter.

Then you can add a small can of oil, and see if you can find the leaks...

 

[Two Buck]

Update: AutoZone/PepBoys manifold gauges don't have the R12 connectors needed for my system, but a guy I met in line there that did. He hooked them up to my system and he says that there is pressure in the system and I should be okay if I recharge it -- I think he said 10 on the low side, I forget what the high side was.

So now I'm looking at Craigslist and Ebay and looking for cans of R12 (and can tap/hose) and I'm seeing R12a offered as a "drop in substitute" for R12. Does anyone have any experience or opinions on R12a?

 

[Miloslavich]

I wouldn't mix them.

R12 is easy enough to get.. just stay the course

 

[SteveH]

Stick with R12 - can you find it on CL at any price in your area? Adding 1 can will immediately tell you what you need to know.

 

[mrlocksmith]

Duracool and other Hydrocarbon based refrigerants are based on a purified propane and isobutane mix. The molecules are larger and the need to repair a small leak goes down. I would get a manifold set for R12 on Ebay and Beg / Borrow / Buy a vacuum pump. Pull a vacuum and see if the system holds the vacuum overnight. If it does not you can do several things.. if the AC system has not been serviced I would replace all the seals and see how that goes.

You can find more info about using Hydrocarbon based refrigerants here.

Duracool-12A (TM), Envirosafe (TM), RedTek (TM), FrostyCool (TM) AKA Hydrocarbon AC Refrigerants

PLEASE NOTE: I AM NOT AN EXPERT ON AUTOMOTIVE REFRIGERANTS. THIS SUBJECT MATTER HAS NOT BEEN REVIEWED BY ANY EXPERTS AND IS PROVIDED FOR EDUCATIONAL PURPOSES ONLY AND MAY CONTAIN ERRORS. USE AT YOUR OWN RISK ! WARNING: HYDROCARBON BASED REFRIGERANTS SUCH AS: Duracool®-12A (TM) , RED-TEK 12A...

forum.ih8mud.com

BTW: The pump can come in handy.. it's not too hard to make or buy a small vacuum chamber. It is great to put phones or other electronics that have gone for a swim.. when you pull a vacuum the water will boil off. You will need to change the oil in the pump after that but it has saved me some $$ on not having to replace a phone.

Mark