Recharging My Ac... Which Is Low Pressure...

[tmonster]

The A/C in my '96 Duratec went out the end of last summer... I think it just needs a recharge.

1) Where is the low pressure switch located? I dont wanna short out the wrong thing
2) Which line is the low pressure line.
3) Should it be a certian temperature outside/inside"

I searched the forums and couldnt find anything to answer my questions....

[tmonster]

Anyone?


I think i'm just gonna go putter around under the hood....

[93 sable]

The low pressure switch is the switch and connector located on or very close to the reciever / dryer.

Jump the connector with the ac on and the compressor should kick on.

The reciever / dryer should be located on the right hand side of the engine compartment, left hand side if your standing in front of the car with the hood open. On my G4 it's in the front near the bumper, but on my G2 and most other systems, it's next to the firewall, and it may be under a cover.

[firespirit]

It should be on the passenger's side, on the firewall. It should have a little yellow or red cap on it.

[tmonster]

well I think I found the low pressure switch.. I unhooked it and shorted it out, nada.

I plugged my gauge onto the ac plug that fit (one is bigger than the other) I got a 0 reading as I expected...

I've checked every fuse the car hast to offer, all the fuses are good...

Last August the A/C got warmer every couple days..it stopped to a point were it was cool...maybe 68 degrees idling... and then the cold air settled in. I do remember turning the A/C on over the winter to cycle the compressor...and If I recall it did turn on.

Wheres my haynes manual when I need it....

[93 sable]

Originally posted by tmonster@Apr 24 2005, 06:16 PM
well I think I found the low pressure switch.. I unhooked it and shorted it out, nada.

So the compressor did not click on? Or it did but the ac system didn't work?

If it didn't click on, then you've got an electrical problem, combined with the zero pressure in the system. Having zero pressure also means that there is a large leak somwhere. recharge the system by yourself and add a dye to it, but NO leak stopper. Use a UV light to see where it's leaking from after a day or 2, But the compressor has to run to do this step, or else the dye won't get circulated.

[tmonster]

The ford service manual states that the outside temperature has to be at least 50 degrees for the compressor to turn on. I guess I gotta wait for this 40 degree week to disapeer....

I bought the recharge kit at advance auto. Alls they had was Recharge with oil and system safe leak sealer.... Is this stuff ok? Here at work (career and technical school) the a/c/heating/plumbing class has the leak detector sniffer tool and other stuff, I may just bring it down there if I can get the compressor to kick on..

[tmonster]

how do I add dye to it??

[tmonster]

I suppose I'll just go without A/C

[holedigger]

Some cans of refrigerant come with dye in them. I read that here somewhere I haven't worked on air conditioning myself.

You may be able to force the a/c to engage despite the temperature. The ambient temperature sensor is in the center of the grille (I'm not sure exactly what they mean by that). If this is like a regular thermistor, the resistance decreases with increasing temperature. That means that if you connect a resistor in parallel with it, you will simulate a higher ambient temperature, fooling the a/c system. To select a suitable resistance, I would measure the resistance across the sensor and find a similar-valued resistor. This will effectively halve the resistance of the sensor when connected in parallel.

Or, you could just wait for it to warm up. It's around 25C here and I'm using the a/c already. Bring the sunshine baby.