Need to charge AC, how to engage clutch

[brmurph]

I need to add some freon to my 09 Journey but can't figure out how to get the clutch on the compressor to engage so I can charge it (I let it get too low).  Normally I would just bypass the low pressure switch but not sure that is the correct way on this vehicle?  

 

 

[John/Horace]

Welcome to the forum. It’s  not Freon, it’s 134a refrigerant.  If there is no pressure in system might be lots of moisture in system. A big contaminant that kills efficiency and system life span. 

 

Can pressure usually creates enough pressure for system to start back up. Adding can of air drier after r134a would help remove some of the moisture.   If can doesn’t start it drawing, and  jumping out low pressure switch harness doesn’t activate compressor, jumping out compressor relay contacts (moveable contacts shown on relay diagram)  I think bypasses all control safety’s.

Lots of pressure in these systems when their running ; wear your jock and your safety glasses.?. Free advice worth everything you pay for it.

Edited March 13, 2023 by John/Horace

[brmurph]

On 3/13/2023 at 1:23 PM, John/Horace said:

Welcome to the forum. It’s  not Freon, it’s 134a refrigerant.  If there is no pressure in system might be lots of moisture in system. A big contaminant that kills efficiency and system life span. 

 

Can pressure usually creates enough pressure for system to start back up. Adding can of air drier after r134a would help remove some of the moisture.   If can doesn’t start it drawing, and  jumping out low pressure switch harness doesn’t activate compressor, jumping out compressor relay contacts (moveable contacts shown on relay diagram)  I think bypasses all control safety’s.

Lots of pressure in these systems when their running ; wear your jock and your safety glasses.?. Free advice worth everything you pay for it.

 

Thanks, sorry for the slow response, I guess I did not get an email notification when you posted (just turned on "Notify me of replies":-).   There is about 75 lbs of pressure (low and high side since compressor/clutch won't engage, not sure if that is enough to engage the clutch?).    What I have tried so far is check signal from the TIPM at the clutch pigtail and received no power when I turned the AC on.  To add to the confusion I have also attempted to put 12 volts directly to the clutch and it still did not engage, to be fair though it was hard to be sure I had a good connection at the pigtail.     Next steps I am going to try is by a new pigtail (if I can find one) and plug it directly into the clutch to verify 12 volts and see if the clutch engages.  I also have a new foxwell code reader on order that supposedly will allow me to send a signal to the clutch and see if it engages.  

 

Still open to suggestions or if anyone knows if 75 lbs is enough to allow the clutch to engage that would be helpful.  At this point I don't know if it is too low on freon (R134A :-), bad clutch, bad transponder (I think that is what Dodge is calling the low pressure switch, 3 wire and apparently can't be jumped?) or bad signal from TIPM.   Also was not able to find a clutch relay in the TIPM, could it be somewhere else?  Some seem to suggest TIPM controls clutch directly with no relay or it uses an internal relay, not sure that is the case though.