A/C not engaging

[Adamwray83]

I have my brother in laws 15 Ecodiesel, doing some work on it after the stealership really screwed things up. Long story short, went to dealer 2 years ago to get broken glow plugs removed (an independent mechanic broke 5 out of 6 off in the heads plus an extractor tool) and he got it back in May of this year with a new engine. A/C hasn't worked since he got it back. Said dealer told him it needs a compressor but when I got a hold of it there was no R1234YF on the system. I leak checked and then charged system by hot wiring compressor. Cools great just doesn't kick engine fan on. So with everything hooked up properly, there is no power to F62 in tipm. I get a full 12 volts and compressor and engine fans kick on for about 5 seconds upon first start up but then back to nothing. I have taken time loose and checked connections, cleaned some body grounds and even swapped a rebuilt tipm ( from MAKS) with the same results. Checked power on light blue wire with red tracer for a/c signal from pcm to tipm and its good at 14 volts when running. I am at my whits end and so is my brother in law. I hope someone can shed some light on this for me. Thanks in advance!

 

[Porter09]

Hello Adamwray, I'm having a similar issue with my 2016 Ram 1500. Left for vacation last and truck was fine. Got back a week later and when I took it down the road, no A/C. Started trouble shooting and found no power on fuse 62 for the A/C. Fuse was good and when I used a power probe to shoot 12v to the fuse, A/C kick on and blows cold. I made a jumper feed for the fuse and checked the Freon with A/c running and it was good at 40psi on the low side. I next replaced the pressure transducer with no change. Interesting thing is if I leave the 12v jumper in place to force the A/C clutch on, it works fine for a while, then the dash flow stops or changes. Blower is running high and no flow from dash vents, defrost, or floor. It almost like the blend doors closed on their own. When I switch modes, it will come back for a while. Very strange stuff. Also had the water in fuel light come on as well. All after the truck sitting unused for a week. I was reading another post about the humidity sensor on dash causing weird A/C issues. I'm afraid maybe the BCM is going out or something. I was really hoping some smart folks on here might provide some guidance. Let me know if you find out anything else or solve your problem, I'll do the same. Take care, Skeeter

 

[Porter09]

UPDATE:

I ended up ordering the OBDLink MX+ and the AlphaODB app. After doing some diagnostics I was able to confirm the AC clutch would not engage when triggered with the AlphaOBD. This pointed squarely to the AC clutch relay. Unfortunately, the AC clutch relay is built into the TIPM and not serviceable. Order a rebuilt TIPM from MAKS and got it installed. Easy swap. AC is working as it should again. Just though I'd share incase anyone else runs into the same issue. Skeeter

 

[Adamwray83]

Hello Porter 09, I am still chasing my issue. I had previously swapped the tipm with one from MAKS but it still didn't work. I'm glad it did for you. My code reader wasn't picking up any ac codes but I borrowed a snap on scanner from a friend and it actually shows I have an ac pressure switch circuit fault. I am tracing wires back to the pcm in hopes of finding something. Thanks for your replies!

 

[KINGKOTA78]

I have my brother in laws 15 Ecodiesel, doing some work on it after the stealership really screwed things up. Long story short, went to dealer 2 years ago to get broken glow plugs removed (an independent mechanic broke 5 out of 6 off in the heads plus an extractor tool) and he got it back in May of this year with a new engine. A/C hasn't worked since he got it back. Said dealer told him it needs a compressor but when I got a hold of it there was no R1234YF on the system. I leak checked and then charged system by hot wiring compressor. Cools great just doesn't kick engine fan on. So with everything hooked up properly, there is no power to F62 in tipm. I get a full 12 volts and compressor and engine fans kick on for about 5 seconds upon first start up but then back to nothing. I have taken time loose and checked connections, cleaned some body grounds and even swapped a rebuilt tipm ( from MAKS) with the same results. Checked power on light blue wire with red tracer for a/c signal from pcm to tipm and its good at 14 volts when running. I am at my whits end and so is my brother in law. I hope someone can shed some light on this for me. Thanks in advance!

Were you able to figure anything out. Idk if you have check the evaporator temp sensor but if it’s malfunctioning it won’t like the compressor kick on. You can place a jumper wire in the plug.

 

[Adamwray83]

Were you able to figure anything out. Idk if you have check the evaporator temp sensor but if it’s malfunctioning it won’t like the compressor kick on. You can place a jumper wire in the plug.

I was able to borrow an actual scanner not just my code reader and it has an active P0533 for ac pressure sensor. I have ran through diag using all data diy and it appears the issue is with the wiring as one test has you jump 2 wires and should set a P0532. If it does that then says to replace sensor. Well it doesn't set that code so then that leads back to wiring. Continuity checks out from sensor over to the brake booster area but I haven't checked on over to the pcm. Hopefully get that done tonight.
Thanks for your reply, I'll double check the reading for that temp sensor too.

 

[Adamwray83]

Well, I finally got the whole issue lined out. I found a connector tucked into the fender and a stray connector tucked underneath the battery box, that just happened to connect to each other. This connector had wiring going to the ac pressure switch hence why I had sensor code. It appeared that whomever(Chrysler Dealership)put cab back on pickup after engine replacement didn't have any clue where the connectors plugged in and just tucked them out of the way so no one would ask questions. They wanted to sell my brother in law a new compressor and charge him to install it. With some persistence I was able to find the issue they(Dealership) created and save my brother in law a few thousand in parts he didn't need. I appreciate the replies and help from this forum!
Adam