'00 Rodeo Air Conditioner not working

[suvguy]

2000 Rodeo, 3.2L 4x2 LS. Push the AC switch in, blue light comes on, fan blows, AC compressor clutch does not engage and no aux cooling fan activation. Checked the 10A fuse under the hood, good. No go in defrost mode as well.

Anyone have this problem before or heard of it? Anyone have wiring diagrams showing the HVAC wiring?

suvguy

[2eyefishclaw]

could be a number of problems may be a leak could be thermostat, tripple pressure switch,wiring problem or seized compressor

[suvguy]

Compressor is not seized, I can turn it by hand. Could be pressure switch. I have not seen an oil slick anywhere around the AC components which would indicate a refrigerant leak. Have any of the pressure switches failed on other vehicles of similar age?

Will look into the pressure switches. Still interested in wiring diagrams for the HVAC system.

suvguy

Originally Posted by 2eyefishclaw

could be a number of problems may be a leak could be thermostat, tripple pressure switch,wiring problem or seized compressor

[rodeo02]

Originally Posted by suvguy

Compressor is not seized, I can turn it by hand. Could be pressure switch. I have not seen an oil slick anywhere around the AC components which would indicate a refrigerant leak. Have any of the pressure switches failed on other vehicles of similar age?

Will look into the pressure switches. Still interested in wiring diagrams for the HVAC system.

suvguy

You would probably smoke the a/c compressor clutch if the compressor was seized. Spinning it by hand without the clutch energized means the pulley free-wheels as it should. Most common cause of no a/c is low system pressure (slow leak). The clutch coil wont energize if system pressure is below minimum setpoint.
G/luck
Joel

[suvguy]

Sure, if the belt was off and you spun the pulley like an idiot, it would spin as it should. But holding the pulley, or with the belt still attached, turning the center section is turning the compresor itself. When the clutch energizes it locks the pulley (outer) to the center section (inner) magnetically and spins the compressor.

System was fine until a month or so ago. No obvious leaks due to the fact there is no oil residue on the condenser, dryer, lines, etc. Will hook up the manifold guages and see what the pressure is. Perhaps the pressure switch went bad.

Does everyone automatically assume the poster is a complete idiot or noob in this forum? geez

suvguy

Originally Posted by rodeo02

You would probably smoke the a/c compressor clutch if the compressor was seized. Spinning it by hand without the clutch energized means the pulley free-wheels as it should. Most common cause of no a/c is low system pressure (slow leak). The clutch coil wont energize if system pressure is below minimum setpoint.
G/luck
Joel

[amigo-2k]

Just a little FYI: 2eyefishclaw is an Isuzu mechanic and rodeo02 I would consider the #2 poster and has a huge knowledge base of Isuzu.

No one here has a clue to what a new person background is, therefor many times they state the obvious.

Now back to your problem.

Have you checked to see if the ac coolant gases are low? Taken it to an AC place to have dye put in to have it leaked checked?

[suvguy]

Hooked up the manifold gauges. No pressure. Guess there is a leak afterall. Must be up high and a slow one as I see no oil around any fittings, hoses, dryer, or condenser.

suvguy

[2eyefishclaw]

once its charged up see if the condensor fan is working if not it could be that head pressure went up high enough to open the pop off valve

[Tom01Rodeo]

My AC went out last summer, turned out to be the compressor. Total bill was around $1300. Thanks goodness for ext. warranty.

[suvguy]

More than likely this problem occured during the winter months as the defroster turns on the AC compressor. Not sure how low temperature (got down to -15*F) affects the compressor oil and refrigerant pressures.

Where is the pop-off valve located on these critters? I don't have my vacuum pump anymore so it looks like I'm in the market for one. Used to have an old refrigerator compressor, but gave it away when I moved. Any descent rotary vane pump out there less than $150 that is any good? Just need 1-2CFM and able to get down to 15-25 micron or so (no venturi type).

What about leak detectors? Anyone have a recommendation for a good unit that is relatively inexpensive? I have the gizmo for the propane torch for detecting R12, but have nothing for R134a.

Thanks
suvguy

Originally Posted by 2eyefishclaw

once its charged up see if the condensor fan is working if not it could be that head pressure went up high enough to open the pop off valve

[suvguy]

Reviving the old thread for an update. My leak was at the high side service port. Either the core o-ring went bad, or the seal at the base of the core went out. Ordered two new cores from AC Source and replaced them both (high and low side). Vacuumed for 30 min and then checked for leaks. None, vacuumed another 45 minutes. Charged with 1.43lbs R134a, working well again. No leaks detected. 40/225psi at ~75*F ambient, output temp at 40-45*F.

First time I've seen a valve core leak.

suvguy

Originally Posted by suvguy

2000 Rodeo, 3.2L 4x2 LS. Push the AC switch in, blue light comes on, fan blows, AC compressor clutch does not engage and no aux cooling fan activation. Checked the 10A fuse under the hood, good. No go in defrost mode as well.

Anyone have this problem before or heard of it? Anyone have wiring diagrams showing the HVAC wiring?

suvguy

[Cat Fuzz]

Originally Posted by suvguy

Does everyone automatically assume the poster is a complete idiot or noob in this forum? geez

suvguy

Yes. Nobody here knows how much you know unless we've had alot of exposure to you. With only 40+ posts, thats not enough for us to know your automotive skill level. I'll stop typing now before I say something rude.