Air Conditioning Problems 87 Comanche

[19comanche87]

My 87 Comanches AC compressor won't kick in. I hooked the compressor up to straight 12 volts and it kicks in. I replaced the relay but I'm still not getting 12 volts to the compressor. Can anyone help me... I've see on other forms that it could be a thermostat switch. What does that look like and where is it located. Any other ideas???

 

Thanks

 

Jim.

[Jeep Driver]

Somewhere you should have a low pressure switch. If you have no freon the compressor will not kick on. If you have no freon and  you bypass the switch for very long you will burn up the pump.

[Jeep Driver]

[dasbulliwagen]

Refrigerant pressure seen at the pressure switch is required, as is a signal from the selector switch inside to tell the relay to come on assuming all other things are as needed to make the system work.

[19comanche87]

Thanks guys. I guess I need to recharge the system. I'm looking at the little window next to the low pressure switch and I can't see anything but a slight tint og green.

[dasbulliwagen]

Ignore the little window. It doesn't help you with anything. Recharge the system to the proper amount and if all the parts are working properly it should work. My own system will leak down over the course of a year so mine needs recharged as well. I converted mine to R134a. There are refrigerant conversion calculators out there to go from R12 to R134a but I have found my system likes about 3 pounds of 134 to work good. Let us know what you figure out.

[19comanche87]

I'm trying the conversion but I can't seem to fill. The 134 will not go in I bought everything for the conversion and put it on but I can't seem to charge the system

[nitroxsteve]

I'm trying the conversion but I can't seem to fill. The 134 will not go in I bought everything for the conversion and put it on but I can't seem to charge the system

Are you opening the valve thats in the connector on the compressor? It should take a 1/4" square drive to to turn the valve open.

[19comanche87]

The valve seems to be frozen shut. It won't turn.

[HOrnbrod]

On my 91, the valve opens by turning it clockwise, just the opposite of most valves.

[19comanche87]

I've been trying to turn it counter clockwise..I'll try that

[19comanche87]

Ok guys I charged my system an it blows cold woo hoo.... Thanks for all you help. I was turning the valve the wrong way.... Once against thanks so much.

[Jeep Driver]

Ok guys I charged my system an it blows cold woo hoo.... Thanks for all you help. I was turning the valve the wrong way.... Once against thanks so much.

Good.

 

Now, I have a compressor on the bench that I will swap out tomorrow.

 

Facing the engine, did you turn CW or CCW to open the valve?

[19comanche87]

I turned the valve clockwise to open.

[Comanchemodder]

Does anyone have a part number for that low/high pressure switch?  Note, my dryer is the "spray paint can" style that fits behind the grill. Embarrassingly, I threw away the switch with my old dryer.

[HOrnbrod]

J3741260. Available at Lambert Chrysler Jeep Dodge, Claremont, NH. 

[martin809]

I have changed over my compressor,drained and or changed all parts. I know I need the retro kit to fill with R134 and I have that. The valves in the kit fit both ports on the back of the comp. how do I know which one to fill?

I realize that the can will only fit one port, but seeing as the port will screw on both valves which one do I screw it on.

 

I hope this makes sense. Pics would be better but I am not at home.

[martin809]

If someone can get a pic of the back of their compressor and tell me where the top or bottom line goes that would be a great help. Not sure If have this correct. Also tell me which port to add R134a too.

BTW it is a 92 Comanche. 4.0

[sloride]

Your compressor will or should have cast letters 'S' suction and 'D' for discharge on the head of the compressor. You'll be charging the suction side so that will help figure out your fittings.

[martin809]

Thanks sloride, I remeber seeing those. This helps alot.