the compressor will NOT engage on my 99 dakota 3.9l,

I've jump wired the compressor clutch directly to the battery, clutch engaged fine

Ive jumped both wire connectors for the sensors on low & high side

Ive checked r134a, GOOD.

What now? Im stumped here, The switch inside the cabin controls all other functions fine, so I'm assuming it is not the problem.

Any help or suggestions is much appreciated.

 

You are sure the A/C clutch is clicking engaging do you see it pulling the compressor meaning it’s engaged?

You are full of Freon?

Did you check the high and low pressures to see if they are ok? You will need a gauge set to do that a rental.

Is the relay ok?

Your compressor may be bad

 

I've been wiring the compressor clutch directly to the battery while the engine is running. It is definately holding the compressor engaged until I unwire it.

I assumed the jumping of both connectors would eliminate the need to further test the high & low pressure switches.

I've just purchased a new relay.

I'm becoming concered about the freon levels. Im using the gauge on the refill bottle I purchased. It was reading really high pressure, but I decided to just run the compressor hot-wired while I dumped about 25 ounces in & not the pressure.

Now when I check the pressure with the truck off, it says 150 psi
But when I hot wire the compressor clutch, The gauge falls down to 0 psi

Also, let me add, the system was completely empty before adding the 25 ounces of freon. I had to remove the compressor to access the thermostat bolts.

 

but then again, if i jumped both of the sensor connectors, shouldn't that fool the system into think there is no freon problem(whether there is or not). Therfore engaging the compressor?

 

If you had the system open pulled apart moist air got into the system.

First did you flush the system out before putting it back together? Never flush the compressor.

Did you dump out all the old oil from the compressor measure and refill it with the correct pag oil.

Did you replace the A/C Receiver Drier / Accumulator if the system was open its a needed replacement.

Did you vacuum the system for one hour and test for leaks before charging it?

Let’s start with that.

 

This is a great place for A/C info

http://www.aircondition.com/tech/cat...47%7DC-Basics/

 

thank you very much

 

one more good info

http://www.aa1car.com/library/ac98.htm

 

R134a Temperature Pressure Chart look on page 3 on this PDF


http://www.mastercool.com/media/99134-A-INST_web.pdf


Here is a good one for understanding your auto A/C very well.

http://www.ariazone.com/manuals/Automotive%20Air%20Conditioning%20Training%20Manua l.pdf