2011 ram 2500 st crew long box 5.7 l gas


Troubleshooting this far

10 am fuse was blown that drove the relay coil power .... fuse location m34
swap relay. test relay on battery .. goes click.

check for continuity thru tipm ..
check wiring..

fan motor is indeed dead.. jumped the connector with alligator clips to battery. will get new one once i figure out the relay issue. see below.

however ...
the relay wont activate when i start the truck and turn on AC.

My question is what conditions need to be present to activate the relay for the fan?.. is it just AC on? or does engine need to be hot? as well?

 

new fan works only after disconnecting battery. runs for approx 1 minute then stops. wont turn back on. i

i am assuming it is supposed to be on while ac is running?

 

I think it should be on any time there is a request for the A/C compressor clutch. It's not on any time the A/C is on, but rather when the pressure switches and temp sensors request the clutch engage.

If your A/C charge is too low or too high, or there is some other issue with the A/C system, it could cause the fan to not be requested. You may need to confirm your line pressures are correct for the A/C. If you have access to a professional scan tool you can monitor if the system is requesting the fan to run or not.

-Rod

 

ac clutch is engaged and there is cool air. only fan does not run

does the tipm monitor current draw of the fan motor?

 

Unfortunately the wiring diagrams and information available through Alldatadiy does not provide detail in to what all inputs go in to the fan request. FCA seems pretty tight-lipped with their "description and operation" information.

-Rod

 

Yeah. I know. I wonder if I put a wire from battery to the relay power feed as a shunt to reduce the current thru the tipm

 

Does the fan only run for 1 minute after reconnecting the battery if the A/C is turned on, or will the fan shut off if the A/C is turned off? Based on your comment about fuse M34 being the one that was blown, that is for the high speed fan relay. Are you sure that's the fan that is supposed to run when the A/C is on? There's also a low speed relay internal to the TIPM that feeds directly to the radiator fan terminal 3 according to the wiring diagram. Maybe it's the low speed side that is not working properly rather than the high speed side which has the user-serviceable relay.

-Rod

 

lol the low speed fan relay on my truck is there its a removable grey colored unit . The high speed relay in in the middle in front of the radiator behind the grille.. i followed the wires out to the fan .. my fan only has two wires not three. its only a one speed fan assy. the low speed is disconnected from factory even tho the relay is present. im not sure why the fuse was originally burnt. m34 according to wiring manual feeds the coils of both low and high speed relays. And as its referred to as the "ac condenser fan" i think it does stay on all the time when ac clutch request is present, but i dont have any literature explaining the timing and sequencing of said relays and operations.

 

Great, so you're telling me not only is information difficult to find on these, I can't trust the information I have!?!

Well, that may not be completely accurate. I took another look at the diagram I have an it does not mark the low speed relay as "non-serviceable" like it does a few other relays. It also clearly shows the high-speed fan relay as not being located in the TIPM, although it doesn't show where it's located. The major difference is it very clearly shows 3 wires on the fan assembly - dark green/dark blue for the high speed (terminal 1), dark blue/dark green for the low speed (terminal 3), and black in terminal 2 to ground.

-Rod

 

Well I can definitely say there are three wires to fan UNTIL the plug on the fan. Then two wires. My diagram says same thing as yours . I thought it had two speeds as well. Also I have learnt from driving the truck yesterday my fan works! I believe it needed to be driven as I think the fan only comes on as you come to a stop after driving ! Long story short as I pull up to a stop I can hear the fan turn on.