Automotive Air Conditioning Information Forum (Archives)

Ronald Draper on Tue September 20, 2011 12:07 AM

Year: 1996
Make: Isuzu
Model: Trooper
Engine Size: 3.2
Refrigerant Type: 134-a
Country of Origin: United States

I just got a 1996 Isuzu Trooper a few days ago from a family member as such I have not located a factory service manual just yet.

The 10 amp fuse inside of the kick panel is blown.

Tried another fuse - same results so it is not just a fatigued fuse.

So what am I looking for? I have not found an wiring diagram on the net as yet?

The compressor is free to turn by hand. There is at least some gas in the system - It quit cooling a few days before I was given the car.

Is there a shorted clutch coil or a low/high pressure switch that is blowing the fuse.

I have and do know how to use a volt ohm meter but before I waste time - I wanted to see if there were some suggestions on how to chase this down in the most effective way.

Thanks

Ron

Dougflas on Tue September 20, 2011 7:21 AM

unplug the clutch and see if fuse blows. also, masure ohms to ground on fuse holder that dos not come from battery. For safety of meter, disconnect battery when using ohms check.

Ronald Draper on Wed September 28, 2011 11:53 PM

Okay - I am a little more prepared to deal with this problem as I now have the factory service manual, have cleaned around the engine compartment due to a leaking ps pump - what a mess that makes, and have examined the compressor wires.

This is a vane compressor - not sure of a brand just yet and it displaces about 8.5 cuin.

These is an sensor that is in the compressor, the "power" lead goes to it, through the sensor and into the clutch coil.

The insilation is very brittle and flaks off with little effort.

I have not "ohmed" the circuit as yet but a general question. The sensor appears to be replaceable but the manual does not discuss this. New is going to be hard to find so I guess to disconnect all leads where I can get to them and sleeve them with heatshrink tubing. I do no see much reason to actually shrink the tubing as there must be some degree of heat in the general area of the compressor to make the wires brittle at such a tender age as a 96.

I am wondering if thereroom to force the tubing in behind the clutch?

I also gather that the fan is rather limited in the power (cfm is 240 per manual) and if there is a stronger fan motor that will replace this fan motor - It is a solid black car and I live in the Dallas Tx area and the prior owner says it is a slow cooldown and just feeling of the air vents - it is rather limited air flow. So while I am fixing the thing - I would like to make any improvemts while I am at it. I would rather have more fan noise with more air flow than simply just sweating it out.

Thanks

Ron

Ronald Draper on Thu September 29, 2011 12:02 AM

I am also wondering if the clutch coil will be available for replacement if that is shorted? No need to mess with the compressor proper if I can just replace the coil.

Is there a larger displacement compressor that would be a "drop in" when and if the compressor proves bad? Or the coil is not available by itself?

Thanks

Ron

mk378 on Thu September 29, 2011 9:02 AM

The sensor on the compressor is a thermal switch that will shut it down in case of overheating. Really you should do what Dougflas suggested and start testing things to find the problem before looking for replacements. Ohm the compressor wire through the switch and coil to ground-- should be more than 3 ohms but not open circuit. Look for other cracked or frayed wires under the hood. On a project of this type it is OK to just patch them with electrical tape. Most of the condenser cooling comes from the engine-driven fan.