A/C question

[ccsolee]

So, I've had my truck almost one week now. It has factory A/C, it's an 86 XLT Lariat. The guy I bought it from told me that the A/C had been extensively repaired/reworked etc by the previous owner who had an obsession with cold A/C. The A/C was cold when I started the truck up the first time I drove it, and it hasn't been cold since then. It was cool to neutral on start up yesterday when it was about 85 degrees outside. I shut the AC off and used the windows instead. It got hotter, I got sunburned and tried to see if the AC was up and running again and it blew HOT air on max and regular settings. I tried adjusting the temperature slide back and forth, but hot was all I got. I checked last night and the condenser? (black tube thing) says it's R12 and R134A compatible. Do I need a recharge or something more involved?

 

[sle2115]

I would start looking for a leak before recharging. Sound like it dumped its refrigerant. Look around all A/C fittings for an oily residue. If you have access to gauges, hook them up and see if you have pressure at all.

 

[ericboutin]

A really simple simple thing to check and is often forgotten....ask me how I know...Anyway mine was doing like you said and the clutch on the compressor was not engaging. The plug on the top had come loose...still on but loose. I popped that back on and wala the compressor engaged and I had air again...Just a thought.

 

[NJKen]

another sometimes easy fix is the clutch cycling swithc on the accumulator. Try giving it a whack and see if the compressor comes back on. If you think its bad you can spin it of and spin a new one on without loosing your charge. There is a valve underneath it.
Ken

 

[ccsolee]

Checked my lines, can't see any signs of a leak, no oil, moisture, nothing. I also checked the plug on top of the compressor and it appears to be in tight. So I might try a recharge and see what happens - I don't have access to gauges to check and see if the pressure is holding. In cooler weather today, the AC blows slightly cooler than ambient...I can't tell if my compressor was coming on or not. I don't believe it was, couldn't hear it engaging at all or anything. A friend of mine from work told me today that if I'm low on refrigerant the compressor won't run because it would run itself all the way out and burn up the compressor.

 

[RLDSL]

If it's been converted to r134a ( there will be a blue cap on the low side port on the accumulator ) you can get one of those big cans of r143a that has a gauge attached to it at the parts store real cheap and use that to check the pressure. then if it needs some, put some in

 

[zpd307]

if you are not sure if the compressor is turning on...... pop the hood when parked somewhere and idling. you hould see and har it kick in. and then go from there.

 

[OLDBULL8]

If the compressor clutch is not engaging, pull the wire connector on the side of the accumulator, thats the little tank by the firewall 3" X 6", take a paper clip and bend it into a U shape, then plug that into the connector contacts, that should make the clutch engage on the compressor. If it engages then the system is low on gas. Charge it with 134A until frost appears coming out the line on the firewall to the accumulator, bleed off the gas until the frost disappears, then you have a full charge. Check the line connectors going to the condenser in front of the radiator, they are o'ring fittings and have to be tight, also same thing on the connections to the compressor. If the system has lost all it's charge, you might want to take those connections apart and make sure the o'rings are on them, they are very small o'rings. Don't leave the connection's open for long as air will get in the system, in fact try to keep the lines plugged into each other.

 

[ccsolee]

I tried the paper clip idea, compressor didn't come on at all. I believe there is pressure in the system, and I checked closer - my accumulator says it's R134A and R12 compatible, but on the switch receptacle for the little plug it says R12. And all my fittings look to be R12 fittings. I think there is pressure in the system still as I tried to bleed off from one of the valves and caught a little hiss. Thanks for all the help - I am trying to hold off taking it to a shop since I've been down the road before and know how much they want for anything involving AC in the summer months.

 

[ericboutin]

When I had my A/C converted the shop left the old R12 fittings on also...I'm assuming it was to force me back to them for a recharge when needed. I found the R134 fittings at Advance I believe...anyway you can buy the correct fittings and they just screw on over top of the R12 fittings. This way you can get R134 cans and re-fill yourself. Any auto parts store will also have as part of the re-fill kit a gauge to let you know what's going on inside. Granted it's not the best gauge in the world but it works for our purposes. Good luck tracking it down...hopefully it's something simple. I just had to finally replace my compressor about a month ago....it seized up completely anyway it was alittle over $600 when all was said and done. Hopefully it won't come to that for you.

 

[Willie Two]

You could also try applying 12 volts + to the clutch right from the battery post for just a few min. to see if the unit will cool down, this will help to confirm if it has any charge at all in the system. The magnetic clutch will also " click " if it is still good.

 

[DragRag]

You really need to out a set f gauges on your ports to see what the pressure is in there. Any pressure below the low pressure switch setting will keep it from coming on. If you jumped the pressure switch properly with the a/cturned on inside the clutch should have engaged. If it did not, make sure you have 12 volts there. If you do, and it did not come one, you may have a bad clutch. I had a bad one on my 01 so I know it is possible. I workon A/C all the time,please try what I said. Getting a set of gauges will really help your situation, your kind of dead w/o them.

 

[Willie Two]

I thing he is looking for a low cost way of a quick diagnosis without buying a set of gauges ( $$$ ) or taking it to a shop for service. 12 volts directly to the clutch is going to quickly determine if it is an electrical problem or a freon issue. Just my 2 cents here....

 

[DragRag]

You can get a cheap set of gauges at harbor or somewhere like that for next to nothing. Aure there not going to be Richie Yellow Jackets, but it opens a whole new world to the guy for sure. Buy some gauges, and be done.

 

[tractorman86]

i would do like dragrag said and first see if you have 12v to the lowpressure switch on the acc. (reciever drier) if there is power there then work off that. AC is not as trickey as most make it sound