1st timer on this Guys . My names Bob i live in sw fla . Ive got a 05 2500 cummins that i bought new it has 330k

[05Diehard]

My 05 2500 cummins w 330k has bin a soldier . It has bin serviced every 5k since new . Has a new built tranny at 250k an injectors at 300k.. recently on a trip back from Ga the ac went out at the Fl line . The has had 2 ac compressors replaced . I checked the compressor an found it locked up . Had a new compressor installed an found return lines froze an no cold blow from dash vents..I was told that the Thermistor was bad , unfortunatley the part is no longer available anywhere . Is there a retro kit to replace the part no longer available ? Am i overlooking something that might cause the freeze up ? Any thoughts appreciated

 

[Harley Harrold]

 

[oe542bob]

I had an ‘03 3500 that would freeze up too sometimes. I asked my dealership service manager(also owner) about it. He had me replaced some little part but it didn’t fix it.
When I noticed it not keeping the cab cool, I would turn off the AC, keep the fan running on high till it was cleared up in the evaporator. Then I pushed the AC button again and most of the time it would be good to go.
Sorry that I don’t actually have a “real fix” for ya.

 

[Papa Red]

Welcome to the forum.

Red

 

[Graygoose]

welcome!!

 

[chri5k]

Did they give you the part number for the Themistor? Maybe someone here can help track one down. Also, might be able to get one off a truck in a wrecking yard.

 

[05Diehard]

Yep , part# 5140727aa . Ive looked on line and called dealers..they tell me they havn stocked the part since 2018.

 

[chri5k]

Here is a good thread on the problem and some creative solutions. https://www.turbodieselregister.com/threads/ac-evaporator-and-probe.267160/

There is also a "work-a-like" generic thermistor but the connector is different so it would have to be spliced to the old connector. It is a Renco L53-2004-100. There are a few of these out there but the prices are very high. A couple of listings in Canada have a better price but not sure about avilability.

Last choice is getting one from a wrecked vehicle.

 

[Joe w.]

Welcome

 

[Bear900]

This sure looks like the same part. You can call them and verify if it fits your model.

Genuine A/C Evaporator Temperature Sensor | eBay

A/C Evaporator Temperature Sensor by Genuine®. If your A/C and heating parts are in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts chain store. On our website you'll find premium Genuine OE (Original...

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And if you're a high roller:

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Get the best deals for 5140727aa at eBay.com. We have a great online selection at the lowest prices with Fast & Free shipping on many items!

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[Bear900]

Here is a good thread on the problem and some creative solutions. https://www.turbodieselregister.com/threads/ac-evaporator-and-probe.267160/

There is also a "work-a-like" generic thermistor but the connector is different so it would have to be spliced to the old connector. It is a Renco L53-2004-100. There are a few of these out there but the prices are very high. A couple of listings in Canada have a better price but not sure about avilability.

Last choice is getting one from a wrecked vehicle.

 

[turkeybird56]

My 05 2500 cummins w 330k has bin a soldier . It has bin serviced every 5k since new . Has a new built tranny at 250k an injectors at 300k.. recently on a trip back from Ga the ac went out at the Fl line . The has had 2 ac compressors replaced . I checked the compressor an found it locked up . Had a new compressor installed an found return lines froze an no cold blow from dash vents..I was told that the Thermistor was bad , unfortunatley the part is no longer available anywhere . Is there a retro kit to replace the part no longer available ? Am i overlooking something that might cause the freeze up ? Any thoughts appreciated

Try here, see if this helps, But U have to research to con firm.

2005 Dodge Ram 2500 Evaporator. Air conditioning - 05073970AB | Mopar Parts Overstock, Lakeland FL

Evaporator. Air conditioning. 2005 Dodge Ram 2500. Genuine Dodge Part - 05073970AB. Ships from Mopar Parts Overstock, Lakeland FL

www.moparpartsoverstock.com

 

[turkeybird56]

I saw the Canadian listings also. Maybe he can work out a deal with one of our Canadian friends, alas, U neva know. Just a thought.

 

[Bear900]

The above referenced thread is Outstanding and headed by Chris MecKenna who appears to be an engineer. He has delved very deeply into icing-up of 3rd gen RAMs, specifically 2002-2005 models.

Part of his discovery was 1) the '05 (I believe the 2500 at least) switched over to a different evap core and thermistor sensor mid-stream and 2), the build/service instructions had the sensor placement in an incorrect position on the EVAP core so that by error it would never work correctly. This would make one think the thermistor temp sensor has failed while all along it is improperly placed.

Finally, and thirdly, is discovery of missing solder in connectors and the controller that needs to be checked.

Whatever you do, read at least posts 136 and 137 for the placement issue. Then go back and read his instructions on testing the thermistor and fixing the areas that may need soldering.

He was also working on a direct replacement for the probe-type temp sensor but not sure how close he is to having that.

It's a great read if you have the time and you've tried everything else. If your mind can handle it, it reads like a novel.

Here's the link again:

https://www.turbodieselregister.com/threads/ac-evaporator-and-probe.267160/page-7

 

[Bear900]

Correction to my prior post....looking over Meckenna's posts once again it appears the probe misplacement was on the 2003 model, but double-check what he says in his post #73.

The solder (or lack of) issues were on the 2005 model and he posts very detailed instructions on his post #103.