06 dodge ram 2500 actually compressor won't cycle

[toolhawk]

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MAKE:dodge
MODEL2500:
YEAR:2006
MILES:200000
ENGINE:diesel
DESCRIBE ISSUE.... AC compressor won't cycle ,system has pressure , how do I test to see if compressor is getting power , a blown fuse ? Can't find one. , AC works great last year never notice a problem all winter with my defroster on, Thank you!!

 

[toolhawk]

I do have power to compressor but no cycling on and off , no cold air

 

[kev2]

confusing post first and second - is there 12v at clutch? Does it engage?

anyway getting started-
Scan for codes - an issue may prevent AC operation. Use a scanner.
Get AC pressure - even if off there is a static pressure and the system requires a specific threshold to engage... If compressor operates post HIGH and LOW readings...

 

[JackC]

If you do have 12 volts at the compressor and no rotation of the compressor, then your compressor clutch is not engaging when it should.

I am not familiar with your system, but if the low pressure switch is opening the ground circuit that could keep the clutch from engaging. I think the switch usually opens the positive side on most systems though. Just a thought.

Of course the clutch could be inop . You might connect power and ground to the clutch to test and see if it is functioning.

 

[kev2]

this uses a pressure transducer instead of a Hi and Low pressure switchs... same principle but no jumping is tolerated...
transducer must show .450v minimum for AC operation AND a scanner is the tool needed....
I have some info once we determine if clutch engages or not....

 

[billr]

Check resistance of the clutch coil.

 

[toolhawk]

Ok sorry for the delay been out of town , have 12 volt at connection when unplugged, but not when plugged in , jump clutch and engages , going to look into it tomorrow, but if I lose voltage under load could I get lucky and just be ground ? (Can i make a ground jumper while connector is connected to test to see if it is bad ground or? ) please be gentle on me I am a fabricator by trade not a electrical trouble shooter , thank you !!

 

[JackC]

have 12 volt at connection when unplugged, but not when plugged in , jump clutch and engages

Sounds like you simply have a bad connection where the 12 volts goes into the compressor.

 

[kev2]

clutch has 12v - but does not engage.....if you jump 12v to clutch it engages?
The clutch gets 12v from AC relay - DK/BK is 12v - BK/BR is ground.

The statement - works when jumped has me confused....12v is 12v weather its from relay or jump wire.... Maybe I am missing something but someone here will have a better mental picture....


Anyway some specs-
(4) The compressor clutch coil is acceptable if the


current draw measured at the clutch coil is 2.0 to 3.9

amperes with the electrical system voltage at 11.5 to

12.5 volts




The air gap specification
is 0.41 to 0.79 millimeter (0.016 to 0.031)in

 

[kev2]

I think jackc has an idea... do you have 12v on both sides of connector ?- they do go bad corrosion broken wires etc -

I could not get that picture before.............to much medicine I guess

 

[toolhawk]

Did a little checking , yes I do have 12 volt with connector unplugged, nothing on either side of connector when plugged in! Where is this ac relay located ?

 

[kev2]

ok with AC commanded ON you have 12v to clutch, BUT the clutch is not engaging (working) ?
maybe the air gap, but sounds like clutch is bad....

The AC relay appears to be working - sending the 12v to the clutch- anyway in underhood fuse box.

 

[toolhawk]

Not on an 06 dodge ram diesel, no ac relay in fuse box , it's not getting 12 volts when connected, it disappears when connectors are connected but it is there when apart , I know it sounds strange. Does some have wiring schematic? Where does power come from? Action temp sensor? Or ?

 

[Mobile Dan]

Dark Blue / Yellow gets power from the Totally Integrated Power Module, connector #9, pin#3. Black wire goes to ground.

I would be using a headlamp bulb to test this circuit. With connector disconnected...jumper from black wire to bulb and another jumper from bulb to Battery positive. Got light? Ground circuit is good.
Now...jumper from black wire to bulb and another jumper from bulb to Dark Blue / Yellow. Got light? You are getting good power from TIPM. No light? Gotta figure out why not...is the AC button on?

 

[kev2]

They do not practice KISS.


is this 5.9L or 6.7 L
The TIPM* monitors the AC clutch circuit, a open, short, hi resistance etc - will cause a code and NO AC request - will not set CEL on.
The trouble tree asks does the clutch engage yes or no?

sounds like a problem with clutch, when connected the TIPM appears to restricts AC clutch voltage -

A scanner is used hopefully someone knows a work around...


Application Coil Resistance Coil Current Draw
3.7L/4.7L/5.7L Gasoline Engines 3.6 ± 0.2 ohms 3.2 - 3.3 amps @ 12V ± 0.5V @ 21° C (70° F)
5.9L/6.7L Diesel Engines 3.0 - 4.0 ohms 3.1 - 4.0 amps @ 12V ± 0.5V @ 21° C (70° F)

*TIPM Totally Integrated Power Module