Can someone inform me where the AC Compressor Clutch relay is physically on the 2007 5.9 cummins?

 

There isn't a relay like you are used to... It is controlled by the TIPM. The same box that has the fuses in it.

 

Well crap no relay. I was really hoping it had a relay, even the napa store said it had a relay from looking what they had documented on their computers. I have my wiring diagram here and have checked both fuses for the AC system, both look good. When I press the switch for the AC in the cab my AC compressor will engage 3 separate times very briefly. Then it the compressor stays shut off completely.

When I jump out the compressor it works like a champ. So I thought it was just the button of the whole electronics panel in the cab. Well I pulled the panel out of my truck and put it in my buddies, and the panel worked just fine. I have also replaced the pressure switch on the compressor and have tested the temp. switch on the coils.

My freon levels are good. When I put a gauge on the system I had 100lbs on each side w/ the compressor off. Can someone help me out w/ this.

 

Well, most times you are going to have a bad evaporator temp sensor. If you find a scanner that will pull HVAC codes I'm sure you will find a related code stored.

 

Yeah I thought it might be the evaporator temp sensor. So I took it out and put it in another pickup of the same model, and their AC system still worked. Wouldn't that be a good way to see if the evap. temp sensor worked?

Where might I find a scanner that can pull HVAC codes? I went to autozone and they tried to pull any codes, but it did not throw any. I think they only scan the motor and drive train sensors. Thanks

 

You will have to pay some diag time at a shop if you don't have a buddy with a good scanner.

Edit: Are you sure you pulled the right sensor? The one inside the HVAC housing....

 

Well not 100%. I pulled a white plastic thing that had wire two wires on the end of it. The plastic was molded like an L. I thought there would just be one sensor in there. If not please let me know and I will look again.

 

The evap temp sensor is a probe stuck in the fins of the evap core.

 

Ok I am still not sure if I removed the right thing. I took the glove box off and then pulled the plastic probe thing and stuck it in another pickup. Is there more to the procedure to pull the evap. temp sensor.

 

Very much... The hvac box needs to be removed from the truck in order to replace the sensor.

 

This picture of a mercedes evap. temp sensor is very similar to what the part looked like that I pulled. Let me know if you can if I pulled the right sensor.

http://www.autohausaz.com/search/pro...erm=2108300772

 

Well thanks for the info. Before I go replacing the sensor sense there is so much work to get to the switch, is there a test procedure that I can see if this sensor is in proper working order. Also do you have any idea what I may have pulled out?

 

I'm sure there is a test for it... I probably won't be able to look it up until after the new year though.

 

That is fine. It is pretty cold here so the AC is not a big concern at this point, but I would like to get it working before it becomes an issue.

Were you able to look at the link that has a picture of the evap. temp sensor for the mercedes? That looks exactly what I took out behind the glove box. I thought for sure it was the evap. temp sensor.

 

I looked at it. I have not seen one of those before but the latest truck I have had that problem with was an 06. I'll go look at my truck later and take a few pics of what I find.