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A/C crapped out *SEARCHED*

ParadiseXJ

ParadiseXJ

NAXJA Forum User
Location
Paradise, CA 95969
My 1990 Renix A/C has always had gremlins. Took it to the shop. Blew cold and would then take a dump and start blowing hot. Shop got everything in line and it worked GREAT for the last two years. It had been running great until last week when I did a tune-up on it and accidentally rubbed against the wire to the compressor and the connector came off.

I said "oops!" and plugged it back in. Took it camping but weather was too cold to need it so I didn't use it. A week later it's 95* and I turned on the air and nothing but hot air.
The compressor kicks in like it always has...but...still hot. Checked the connection and it's all good.

WTF did I do? Any ideas? What do I test? Is there a fuse? 1990 4.0

Plenty of freon, good pressure etc.
 
Also check the lines between the condenser and the receiver/dryer - the ones on my '92 finally just rotted out (apparently, it would hold vacuum, but under pressure it leaked).
 
Like I said...

ParadiseXJ said:
Checked the connection and it's all good...

Plenty of freon, good pressure etc.
Click to expand...

Electric fan goes on, compressor kicks in, sight glass full, freon moving, blower goes on, everything goes on. Just blows hot.

It worked great and THEN...poof...no worky.
 
Are the AC lines cold?

Check your blend door controls. Maybe it's stuck on HOT.
 
Saudade said:
Are the AC lines cold?

Check your blend door controls. Maybe it's stuck on HOT.
Click to expand...

I did not check the lines...I will do that. We were in the middle of evacuating (big wildfire here) and I haven't had the time since I was under the hood cursing on Friday.

So if the lines are cold/hot, what then? The doors? I have good vacuum all around, I relocated the "ball" to the firewall last summer when I DID have a problem and replaced all my vac lines. There is a possibility that I bumped a vac line when I was in there but it doesn't default to defrost, blows hot air right at me (much like I do here).

Thanks for the info
 
Sounds like you knocked a vacuum line loose near the firewall & expansion valve. The damper doors are vacuum operated in the dash area, and spring return to default locations. Default is heat I think, and definately uses hot outside air and does not recirculate inside air. Could also be a wire linkage proplem on the heat AC...Cool / hot slider controls. Mine was a leaking vacuum line and bad damper door vacuum motor / valve assy, leaking diaphram.
 
My last problem was a brand new vacuum hose, rubber, the ID was not smooth, it was defective on the ID.
 
The blend door is not vacuum operated. The cable could have slipped off and it's blocking the evap.

Turn on the AC and left run for a few minutes. The line from the compressor to the condenser should be hot (be careful). The line from the compressor to the expansion valve on the firewall should be cold. If they are, then the AC is probably OK and you have some blockage in the heater box.

If not, then despite the view in the sight glass, you may be low on charge.
 
Saudade said:
The blend door is not vacuum operated. The cable could have slipped off and it's blocking the evap.

Turn on the AC and left run for a few minutes. The line from the compressor to the condenser should be hot (be careful). The line from the compressor to the expansion valve on the firewall should be cold. If they are, then the AC is probably OK and you have some blockage in the heater box.

If not, then despite the view in the sight glass, you may be low on charge.
Click to expand...

He should also check the Fresh air / recircualte door under the dash on the passenger side which is vacuum operated, as it defaults to outside air if it looses vacuum. Then it acts like it is low on refrigerant, especially at idle in heavy traffic at 100 F like today here, Ouch! I had problems with it on both my jeeps.
 
Saudade said:
The blend door is not vacuum operated. The cable could have slipped off and it's blocking the evap.

Turn on the AC and left run for a few minutes. The line from the compressor to the condenser should be hot (be careful). The line from the compressor to the expansion valve on the firewall should be cold. If they are, then the AC is probably OK and you have some blockage in the heater box.

If not, then despite the view in the sight glass, you may be low on charge.
Click to expand...

Well, was wrong again. I checked the lines after driving for about 15 minutes. Both warm. So, put the gauge on. Pressure barely moved. So, apparently I have leak. (*&^%#^%#@^%#@.

More later, Thanks guys.
 
You may wish to consider converting to R-134a while you're at it. R-12 is available on places like ebay but it's pretty expensive (like $20 a can).
 
Saudade said:
You may wish to consider converting to R-134a while you're at it. R-12 is available on places like ebay but it's pretty expensive (like $20 a can).
Click to expand...

OK maybe you can walk me through this. It's already converted to R134a.

I bought the can with the little gauge dealio on it. I hooked it up to what I thought is the low pressure side (the blue cap). The 134a nozzle only fits on the one side (blue, and much smaller than the side with the red cap.). So I hooked it up, started the engine and twisted the little needle valve on the hose (that came with the can). As soon as I twisted the valve to the open position the neddle pegged past the "Danger Zone". So, I freaked, unhooked the connector. The needle is still pegged. Now I'm kinda lost. I don't want to stand there holding a can with a pegged gauge.

I'm reading that I don't want to hook it to the high side but it's the only side that fits the blue connector. So, I did a no-no and released a little pressure from the can, and it went down but it went back up to pegged. It's disconnected now so it's obvously reading the pressure in the can and not my system...or did I overpressurize it (the can) by hooking it to the system?

My question is if I have it hooked up correctly does the pressure abate as it goes into the system? If it doesn't go down am I holding a bomb? I'm friggin stumped here and I need some help. Seems simple enough but something's not right.
 
Ah... If you have the adapter already installed, there a cap hiding a shaft on the valve. The low pressure is the one connecting the compressor to the expansion valve. The can should only fit one, the one on the low side. Take the cap off, if it's still there. You'll find the shaft with a square drive end on it. Hook up the can. Then turn the shaft as if you were tightening it. This will open the valve and give you a valid reading and allow the refrigerant to be drawn into the system. Make sure you close the valve before you disconnect the can. As you can see, I still run R-12.

The valves look like this.

ac_fitting001Small.jpg


Stemvalve.jpg
 
Saudade said:
Ah... If you have the adapter already installed, there a cap hiding a shaft on the valve. The low pressure is the one connecting the compressor to the expansion valve. The can should only fit one, the one on the low side. Take the cap off, if it's still there. You'll find the shaft with a square drive end on it. Hook up the can. Then turn the shaft as if you were tightening it. This will open the valve and give you a valid reading and allow the refrigerant to be drawn into the system. Make sure you close the valve before you disconnect the can. As you can see, I still run R-12.

The valves look like this.
Click to expand...
 
Saudade said:
Ah... If you have the adapter already installed, there a cap hiding a shaft on the valve. The low pressure is the one connecting the compressor to the expansion valve. The can should only fit one, the one on the low side. Take the cap off, if it's still there. You'll find the shaft with a square drive end on it. Hook up the can. Then turn the shaft as if you were tightening it. This will open the valve and give you a valid reading and allow the refrigerant to be drawn into the system. Make sure you close the valve before you disconnect the can. As you can see, I still run R-12.

The valves look like this.

ac_fitting001Small.jpg


Stemvalve.jpg
Click to expand...
 
Sorry about the double quotes/post

YOU ARE THE MAN

There are now penquins waiting to move into my XJ. I'm putting on my parka to go for a drive. Thank you, and I mean freakin ALOT

:clap:

Unfortunately I now wonder where that refrigerant went, it took the whole 14oz. can and it's freezing in my Jeep, but I now have to find out where it went.

Happy camper now though!!!!!!!! Wooo hoooo
 
OK
I think I'm good to go now. I found a faint trace of a leak at the connector to the high pressure side. I put a wrench to it and found that I could turn it almost two full turns before tight. Soaped it up looking further for a leak.

I cleaned it all up and ran it for a 1/2 hour or so, then went for a drive, about 30 miles at varied speeds with the A/C on full blast (brrrrrrrr) and checked the leak area, nothin.
Oddly the trace of leak showed up much better with a LED light as opposed to a regular flash light, almost glowing. The pressure has held over 24 hrs., dead on!!

So, I learned alot from this experience, probably saved myself a couple hundred bucks in the process and now my A/C works better than it EVER has. Thanks again Saudale
 
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