Frustrating '97 Ford Exploder Sport AC problems...

[siriusmetallica]

Greetings!

Two years ago I bought a 1997 Ford Explorer Sport with both an AC/heater problem. The heater had a couple of broken plastic components in it and around the blower motor that left it on continuously but it has since been fixed. The AC however is still causing problems. Whenever I try turn it on, it just power cycles and never actually runs (there is air circulation from the blower motor but it's not). The unit itself is drawing power and the engine does bog down slightly while it enters the cycle but just before the AC can actually run, it turns off and the process repeats. Also, the unit will only hold a charge overnight before the gauge reads low pressure. I've speculated and I've been told it could be anything from a bad compressor to what I think is an electrical short and bad connections, etc. Does anyone know why it does this or what a possible solution would be? How much does it cost to have this repaired typically?

(The car itself is a 1997 Ford Explorer Sport with the SOHC 4.0L V6.)

Any help whatsoever would be greatly appreciated as this has become quite the problem.

 

[manaen]

try turn it on, it just power cycles and never actually runs

are you talking about the AC pump under the hood?

the unit will only hold a charge overnight before the gauge reads low pressure

I assume your talking about r134a coolant gauge? if so you need to fix the leak and flush the system then recharge it before it will continue.

The pump turns off due to low pressure, it is a protective measure.

 

[siriusmetallica]

Thank you Manaen for the reply!

I am referring to the AC unit itself under the hood. You can tell it's drawing power and power cycling but it won't stay on, it just switches on and off itself.

That would sense although the pressure gauge does read within the acceptable normal range for charge immediately after charging it. The system also retains that charge for a few hours while testing it and thus far there haven't been any obvious leaks. But at any rate, even with the system being flushed and charged the unit itself still has the same problem irregardless unfortunately.

What sort of electrical components are there for the AC unit? I'm suspecting I might have a bad low pressure switch or a short but would either cause these symptoms?

 

[manaen]

you cannot test the pressure unless the system is running. The low pressure reading should be read while the system is on max AC and the pump is pumping. If the pump will not engage there are really only a few reasons why...

1) the most common reason is the psi sensor is reading a low value therefore the pump is shutoff to avoid burning up the pump, In this situation the pump will normally turn on for a short time, and then turn back off. What is happening is the pressure in the low side of the line drops when the pump kicks in which causes the low psi sensor to trip. You need to add fluid to fix the problem.
2) there is also a high pressure cutoff switch so if there is too much PSI the pump is shut off so the system does not burst
3) there is no power getting to the pump clutch caused by bad wiring, sounds like your pump is kicking in so this is not your problem
4) You have a bad AC clutch, this is not your problem either because as you said the pump kicks in for a few seconds.


so that leaves you with two options
1) your fluid is low, and your low psi sensor is tripping
2) you have a blockage in the orifice which is causing a high psi situation.