JKOwners Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
172 Posts
Discussion Starter #1
I don't know what happened but in the last week the entire heating and cooling system has gone out - no lights on the controls, no blower fan, nothing. I've checked all the apparently relevant fuses but don't see what is the cause. Anyone had similar issues? Maybe give me some idea where to look next?
 

·
Registered
Joined
·
1,186 Posts
First is the TIPM fuse #m34 (a 10amp fuse) there is also a run relay in the TIPM, check relay connection 86 and 30 for power, if power is good check relay, if relay is good then check the pk/yl wire at the back of the ac control - if previous check has power, then you should have power at the pk/yl wire. Also check for ground at the bk/wt wire on back of the ac control, this is the ground wire.

At this point it gets a little tougher because the problem then could be in either the cluster or the ac control panel itself, and will take a little further testing to determine which one is the culprit.

But first make sure its not the wiring from the TIPM - more common problem.

Also reply back with year, etc, and if any recent work has been done especially electrical in nature. I assumed an 09 JKU. But unless its a 2012 wire colors should be the same.
 

·
Registered
Joined
·
148 Posts
Check all fuses related to your Year make and model...
I can run through the online diagrams and tell ya where to look for the most likely causes.
if nothing else, bring it in to your dealer, ask them to hook it to witech and see what codes are set in the TIPM, its not unusual for a HVAC module to "die"
 

·
Registered
Joined
·
172 Posts
Discussion Starter #6
Now I'm totally confused... I haven't had a chance to investigate this issue but suddenly it started working again! Heat, AC, Defrost, it's all operational! I am glad it is but I hate phantom problems.
 

·
Registered
Joined
·
9 Posts
Mine's an '07, had same prob a while back..while a tech was trying to figure out my no-start prob he found a ground wire disconnected (no other info to offer on this)..anyway, took the heep after repaired wire thinking whatever that was, at least the thing is starting again. Turns out the ground wire must have been related to the same prob you're having b/c that was working again (which I did not expect) and soon after the mysterious no-start issue reared it's ugly head again. ??

This vehicle is making me crazy..and making me want to learn ALL about the tech aspects of the JK. Hate being in the dark!!
 

·
Registered
Joined
·
1,186 Posts
Now I feel stupid but ... where is relay connection 86 and 30?
Sorry bout that.. All relay's have two main parts, one is the "coil" side, its the low amp switch part of the relay, and 85 and 86 are the "coil" leads, with 86 being the power side and 85 is ground. Then you have 87 and 30 which is the "switched" higher amp portion. 87 is power and 30 is the leg that goes to the load.
Just to mess things up, some relays have a fifth leg, 87a and some are numbered with 1,2,3,4 instead of the standard 85.86.87.30

Check out 12volt site here for more and better detail.

of course www dot the12volt.com/relays/relaydiagram25.html

don't remember the rule on posting links
 

·
Registered
Joined
·
172 Posts
Discussion Starter #9
Okay, so I think I've at least figured out what's going on even if I don't know how to fix it. I use a Superchips programmer and I've realized that when I program the Jeep for the trails using Superchips crawl tune is when my HVAC goes out. If I reprogram back to a mileage tune they resume working. Go figure! Now I know who's chain to rattle!
 
1 - 9 of 9 Posts
Top