ya it appears to be moving, the fan and comp start. the engine speed changes. but i have to bypass the safety switch.

also i put a can of 134 on and opened it and nothing went in. so maybe the comp is not engaging? would this cause the pressures to show high if the comp is not engaging?

 

The pressures on both sides are equal, so it means the compressor is not working.

The ECU does adjust the idle to compensate for the extra load the a/c puts on the system. So the change in engine speed may be from the ECU and not the a/c compressor.

Start with the simplest test first. Watch the compressor clutch plate (to the right of #3 snap ring in the pic) when the car is running. With the a/c turned off, it should not spin. With the a/c turned on, that plate should spin at the same rate as the belt pulley. Use a flashlight to make watching it easier.

 

ok, is it does not come on what do i try next? check to make sure it has 12v? is not the relay? thanks for your help.

also the low side should show around 15-30? high side 180ish?

 

There is a pressure chart in the shop manual that you can use. It is kind of confusing, because you have to know the outside air temperature and humidity. The temperature at the vent. Also the high and low pressure.

The range on the chart for low is 0-60 psi. The high side is 140-430 psi.

There is a tsb 96-012 that has another test that you can do.

I would unplug the connector to the compressor, turn on the a/c. Touch + probe on volt meter to connector, touch - probe to ground bolt on valve cover. See if you have 12V. That will determine the next step.

 

it is not a proper way to by bypass the switch and hooking up the gauges ,,
did you totally remove the freon, put under vacc and recharge like i advised you on previous post??? only add 16-20 ozs of r134A,,
Once that is done and compressor does not work you need to diagnose the issue , if compressor works then hook up the gauges and read the pressures ,,

 

ok ill check tomorrow. i have not evacuated the system. dont have access to that equipment. trying to figure it out before i spend a lot of money. i know it may not be the right way.

 

I would plug back in the pressure switch.

Start with testing for 12V on the red wire that goes to the compressor with the car running and a/c turned on.

 

ok, if NO power then what?

if power then?

 

If power, then something is up with the magnetic clutch coil or possibly the clutch gap.

If no power (more likely IMO), you will go to the relay.

It is bolted on a bracket on the drivers side cooling fan casing. There are two relays, so identify the compressor clutch relay by the wire colors (red/blu, wht, red, blk/yel).

You will test the electrical connector going to the relay. It has 4 wires. The Blk/yel and wht wires should have 12V to ground (valve cover bolt will work) when the car is running. Red/blu wire should be open to ground when the car is running and the a/c is off. Red/blu should be closed to ground when the a/c switch is turned on. Red wire should be closed to the plug that leads to the compressor.

 

it has power. i cant tell if the clutch is engaging or not.