Here is one more to think about - Do you have good air flow out the vents? Does the air flow go down the longer you drive?

 

Airflow is something I would describe as poor all of the time. Or at least until I cut out those screens as seen in the first set of pics on page 1. While the flow doesn't exactly blow me away it is better. It always blows the same and I have not noticed it diminishing as time goes on.

This is interesting though....on that 2 hour trip that my wife went on with me a piece of ice fell on her foot.

 

The fin temp sensor should not be allowing the system to freeze like that regardless of how much air is going across the evaporator. Have fin temp verified with a scanner. Obviously it should read below freezing if airflow starts to drop. If it does not read that low there is a problem with it or the wiring.

 

You are correct. The fin temp sensor should have shut the compressor off long before this happened. It may be in the wrong spot or they forgot to plug it in.

 

Just for clarification because, Is this "fin Temp Sensor" a probe that is wired to the ECM? There for the ECM would see that the Evap is too cold and shut down the compressor?

 

One other tidbit of info. When my recirc button is on and am traveling faster than 60mph, there is a loud whistle from the passenger side. Dealership says my cowl is broken. I think it has something to do with my problem. And no, the whistle is not my turbo and it does not go away when the window is cracked or down but actually gets louder.

 

At the dealer right now. Low side 15 and High side 180. Evaporator temp sensor is showing 73 degrees. Also, the compressor in cycles when the fan switch is on the low setting, otherwise it stays on the whole time.

 

That is correct.

 

What is the outside temp? Looks like the fin temp is not reading correctly. I won't say that is the only problem, but it sure isn't helping the situation.

 

Both are about 20 PSI low.

A good High Temperature Reading for 134a = twice the ambient temperature + 50.

A good Low Temperature reading should be between 30-40 psig.
This means the temperature of the refrigerant entering the evaporator is between 35 and 40° F.

At 15 on the low side that would = 14.94 F

 

Outside temp was 84 degrees and rising.

 

Their suggested fix was 2 options. One, cut a hole in the plenum and move the fin temp sensor until they find the coldest spot. Two, replace and update the whole plenum box fin temp sensor to an 07 style (nearly $1000--with free labor), or three take the dash off again and try to relocate the sensor so that they would put a hole in my plenum.

Does anyone have any suggestions on relocated the sensor, on a 06 Mega Cab specifically. They found one service note on DC Connect for an 03 Quad Cab but I can't imagine it has the same evaporator as an 06....any suggestions from someone who has done this??

 

What is the fin temp sensor reading?
I would cut a hole, assuming that none of this is waranty. If it is, they should pay to fix it, what ever it takes.

 

It is low..... No doubt about it.

 

Perty sure it is the same Evap from 03' to 07' on the 5.9 trucks.