Problems... Problems. And i have spent 6 hours searching old forums

[nitrox2595]

Hello Folks,
I have an 07.5 Megacab Dually 6.7 with 138k on it. I am having A/c issues. My mechanic said he is not getting power from to the HVAC control module, but the A/C light and defroster light still work. I moved the fan position knob, and half the condenser and 1 line freezes up, but no air is coming out of vents. I used to drive the truck every day, but now it is like 3 x a week. Some times when i start it, i get the CEL, and the lightning bolt lights on dash, other times not. Any ideas?? I am going nuts again. Also, the exhaust brake light comes on, but no brake slowing down. The guy who put my trans in, said the turbo was on its way out. Any ideas on that?

 

[Motorhead]

My first suggestion with several electronic issues is to check all of your battery and ground connections from the batteries to the chassis and to the engine. Just a question, how old are your batteries?
Are you saying you have NO fan air movement at all?

 

[nitrox2595]

My first suggestion with several electronic issues is to check all of your battery and ground connections from the batteries to the chassis and to the engine. Just a question, how old are your batteries?
Are you saying you have NO fan air movement at all?

Correct, No fan movement at all. And the batteries are probably 3 to 4 years old.

 

[Motorhead]

Have you added ANYTHING to the electrical system (Non Stock) that is going through the TIPM? Seeing as you are on the East Coast with bad winter salted roads, I would carefully check any and all under hood electrical connections. You can lift the TIPM out of its holder and check all the wiring gang plugs that connect to the under side of the TIPM. Dis-connect both batteries BEFORE messing with the TIPM.

 

[TWebster]

You might start by pulling the fan motor out from under the dash----super simple---- and check to see if it is functional, then the resistor pack, then the output of the hvac controls. before you stat doing this though, pull the clutch energizing wire off the compressor. running the compressor without the inside fan running can lead to a liquid flood back because its not absorbing any heat, and cook the compressor.

 

[nitrox2595]

Unfortunately, I have about 25 extra "things" that are added (electrical), but only 2 are directly fused to the TIPM. I now live in North Carolina. I will have my mechanic do what you guys said, The sad part is, is that I put 3 Transmissions in the past 5 years, including an $11k ATS. I really hope that the cause of all these issues is a bad ground. He said that he had a tool that traces bad grounds, and/or shorts. I hope that works. Thank You all for the help.