Automotive Air Conditioning Information Forum (Archives)

tscaravan on Sat May 10, 2014 7:04 PM

Year: 2005
Make: Dodge
Model: Grand Caravan
Engine Size: 3.8
Refrigerant Type: R134
Ambient Temp: 75
Pressure Low: 70
Pressure High: 70
Country of Origin: United States

I need a little help with diagnostics.

Static pressure 70psi. Clutch engages, engine loads down a bit as normal, no odd noises from compressor. Pressures don't move at all, not even a little difference between hi and lo.

Does this make sense? Can the compressor be shot in a way as to make no noises and not put out even a little pressure/suction? Any way to diagnose for bad compressor vs. something else in the system?

Any hints would be appreciated, thanks.

Dougflas on Sat May 10, 2014 7:06 PM

Are the hanwheels of your guages closed?

tscaravan on Sat May 10, 2014 7:15 PM

Haha, no, they're on. I actually watched the pressures both go up about 5psi as I ran the car in the garage and underhood got hot.

mk378 on Sat May 10, 2014 7:31 PM

The handwheels must be kept closed to take pressure readings. Opening the handwheels allows refrigerant to flow through the center section of the manifold, which will cause incorrect readings. They should only be opened when you're doing something with the yellow hose. But with that said, pressure should still move at least a little when the compressor starts.

tscaravan on Sat May 10, 2014 7:35 PM

Sorry, I misread that. Yes the handwheels are in the position where they are NOT connected together or to the charging hose.

tscaravan on Sat May 10, 2014 8:04 PM

OK, just went and made sure the manifold doesn't have a leak. Gave it a quick shot of 134 to the low side, that side gauge jumped, the other stayed put. So no internal leak.