FJ60 V8 Conversion A/C ? (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

pardon the zip ties and stuff, my truck is a work on it here and there and I was trying to keep some things away from the passenger side exhaust manifold. Anyway see some pics for teh 5.7 vortec. If I find some pics of the modified hose by itself I'll post up. Anyway I used a GM OEM a/c compressor hose and modifed that. I should have replaced the two hoses that (one ) runs from the firewall to teh dryer (two) runs from the dryer to the condensor, but at the time for whatever reason I did not. Guess I 'll see how long the old hoses last.
20200501_151007.jpg
20200501_150814.jpg
20200501_150752.jpg
 
this series of pics show the engine bay better and show the GM OEM A?C Compressor hose I modified. I posted these earlier but for whatever reason I had problems. should work now ... Again this is on the 5.7 vortec.
20200329_160253.jpg
20200329_160302.jpg
AC-compressorHose.jpg
 
Thank you for posting the pics! I'm putting all this together right now, except I'm using the '99 serpentine set up on an ol' school carb/HEI 350. Idle up will be much easier for me, but I still have to work out the AC amplifier, and trigger from the HEI. Also, I have a wiring harness coming out of the BACK of the GM compressor too, haven't figured out what that is yet...
 
The pics above that I posted show a 1999 5.7 vortec (physical setup), I bought the engine from a salvage yard. The engine is from a 99 GMC Yukon. A year or two after I did the swap, I bought a new GM long-block assembly and we swapped the top end over to the new long-block. Programming wise, the engine is setup like a 97 year model, due to some limitation in the wiring harness or supposedly the best approach at the time.

The idle up feature would be nice but I've not really devoted any time to solving that as of yet. A/C works fine without it, but I would like that to work on my setup (right now it does not), I may look into that this summer. Of course mine is fuel injected, right off hand based on memory I don't I have any signal or input that tells the ECM that A/C is enabled. I use a stand alone engine harness that operates the eninge /ECM.

See post above in this thread ...I think its #9 that gives some advice on the ac amp and trigger from coil neg wire as I recall.
 
I know the pics are not great showing the mod to the end of the a/c hose that feeds the condensor. But we did swap the gm ends out for the toyota ends on the GM OEM AC hose. I wish I would have replaced the other hoses at that same time but I just went on and used them and so far everything is working.
 
I know the pics are not great showing the mod to the end of the a/c hose that feeds the condensor. But we did swap the gm ends out for the toyota ends on the GM OEM AC hose. I wish I would have replaced the other hoses at that same time but I just went on and used them and so far everything is working.
Do you have an electric radiator fan?
 
I’m in the process of sorting my AC system out.
I am using Derale electric fans. I was told that I need to install a trinary switch to activate the fans to come on when I turn my ac on...

Is anyone here running electric fans and did you need to install a trinary switch?
 
I did not when I did my LS swap in my 80. I pulled a signal from the AC compressor to fire a relay to control the fans.

What did you use to pull a signal? Did you use the harness relay or did you install a standalone relay?
I am using the GM AC compressor. It is wired to my FJ60 AC button in the dash.
 
Took the 12v signal that energizes the clutch on the compressor to fire a relay. Relay controls fans. Was running dual SPAL fans, but connected only one of the 2 fans to the relay. The other fan was controlled by the PCM.
 
I'm not an electric fan guy, but depending on which fan controller you're using with the Derale fans, many of them have an input for ac trigger to run one fan, or low speed, check the documentation for the controller. You'd just pull that signal from the AC clutch wire.
 
I'm not an electric fan guy, but depending on which fan controller you're using with the Derale fans, many of them have an input for ac trigger to run one fan, or low speed, check the documentation for the controller. You'd just pull that signal from the AC clutch wire.
Thank beerfix,

I just found out today that I need to install a trinary switch to my ac dryer....

Vintage Air sells them if anyone else needs one.

Ill post my test results as soon as I install it.
 
The fan was simple. Just splice a wire into the compressor power wire, and use it for your fan signal wire (Relay) Fan will run when the compressor does. I have one fan wired to the compressor, and the other to the ecu, coming on at 201 and off at 195.

Without a fan when the AC was on, the high side pressure would go WAY up, and eventually would purge because it was sooo high. Or blow a hose or some other weak spot
 
The fan was simple. Just splice a wire into the compressor power wire, and use it for your fan signal wire (Relay) Fan will run when the compressor does. I have one fan wired to the compressor, and the other to the ecu, coming on at 201 and off at 195.

Without a fan when the AC was on, the high side pressure would go WAY up, and eventually would purge because it was sooo high. Or blow a hose or some other weak spot
Got any pictures?
 
Well not really.

There is only one power wire on the factory AC plug at the compressor. This gets power when there is a call for AC. So that can be used as a positive signal for a relay.

Just wire a relay for the electric fan. For the signal wire for the relay, pin 85, splice a wire onto the factory AC plug. Run that wire to the relay pin 85. When the ac compressor turns on, so does the fan. Compressor turns off or cycles off, fan turns off

A006389D-21C1-40F5-95F1-EA5DF34D9971.jpeg
 
Last edited:
Well not really.

There is only one power wire on the factory AC plug at the compressor. This gets power when there is a call for AC. So that can be used as a positive signal for a relay.

Just wire a relay for the electric fan. For the signal wire for the relay, pin 85, splice a wire onto the factory AC plug. Run that wire to the relay pin 85. When the ac compressor turns on, so does the fan. Compressor turns off or cycles off, fan turns off

View attachment 2403524
 
Well not really.

There is only one power wire on the factory AC plug at the compressor. This gets power when there is a call for AC. So that can be used as a positive signal for a relay.

Just wire a relay for the electric fan. For the signal wire for the relay, pin 85, splice a wire onto the factory AC plug. Run that wire to the relay pin 85. When the ac compressor turns on, so does the fan. Compressor turns off or cycles off, fan turns off

View attachment 2403524
That’s a great diagram! Thanks for sharing. I’m gonna do this tomorrow...,
 
Do you have an electric radiator fan?


no, i use the GM fan clutch and GM radiator fan that is stock with the engine I have (99...95 or so 5.7 vortec, all use the same setup) with a custom radiator shroud (for engine cooling). I do have an electric fan in front of the condensor that is a pusher type fan that I can turn on when I want to for additional cooling, simple toggle on / off.
 
if you are running electric radiator cooling fans....you must have air flow across the condensor or you will have some problems with A/C. as noted above most of the electric cooling fan controllers have a signal input for the compressor (ie the fans come on when the compressor is engaged, if they are not otherwise on). Bottom line the condensor has to have air flow when the A/C is engaged. This is a non issue with mechanical cooling as there is always some air moving across the condensor with mechanical cooling, and the fan clutch controls the cooling fan based on temps beyond that.

There are some different approaches in electric fan cooling and a/c, I think some of them turn the cooling fans on low speed and they stay on low speed when the a/c is on, then high speed is engaged on the cooling fans if the temps climb beyond a certain temp range.

summary is that with electric fans and a/c, you must have some additional controls on cooling fan engagement beyond simple temp range based on engine temps because the a/c will "cook itself" otherwise. Turn on any modern car with electric radiator cooling fans and then turn on the a/c and watch what happens to the electric cooling fans.
 
The shop that's working on doing the H55 swap in my FJ62 is going to be making an attempt to get our air conditioning going. It has a TBI 350, and when the PO did the swap they didn't bother to hook up the A/C. I'm super curious what the shop is going to do, but I'm nervous for that message that it's not going to work. Am I overcomplicating it in my mind? haha
 

Users who are viewing this thread

Back
Top Bottom