I have an 09 Ram with dual zone climate, the blower motor, resistor, and head unit have been replaced. The software has been flashed by the dealer.

On startup the ac or heat turns on, the blower motor comes on for a moment. After a few seconds the blower stops working, but the compressor stays engaged. After a minute to several minutes, the blower comes back on and then functions normally from the fan speed control.

Any suggestions? I have googled and searched and while I have found a few people with the exact same problem, I cannot find a solution.

Thanks!

 

Were the blower motor, blower motor resistor, head unit, and software update all in an attempt to solve this issue? Do you have a multimeter or test light that you can use to backprobe the blower motor to determine if it's getting power even when it's not running?

-Rod

 

Yes they were all replaced. The truck is my dad's, and he unloaded the parts cannon on it, much to my disapproval.
The blower motor was an issue because it was getting hot and stopping after a few minutes of use. The flash was because of a TSB for it, so it was something that needed to be done.

As for the dvom, yes we can check for voltage at the blower on startup. Not a bad idea to verify, however I am assuming (i know how dangerous that is) that there will be a voltage issue, as the blower motor works perfectly once it wakes up, and immediately upon restarting the truck, it needs to wake up again. As if it is a programming error.

So when we see a lack of voltage at the blower motor, where do we go from there?

Thank you!

 

Trace it back to the source, find out where you are losing power.

 

My question regarding the replaced components was not if they were replaced but rather were they replaced in an attempt to fix this issue, or are they all relatively new but installed for various reasons. It sounds like it was kind of a mix, there were other reasons they were replaced, but it's unclear whether this issue was present before all of them were replaced or if that is known. For example, you suspect a programming error, but the "software was reflashed by the dealer." So was there any change to the blower motor operation after the reflash? Did the dealer comment on why or why not? Probably not if that was not the reason for the reflash since it was for a TSB. Also, since you mention programming, this is the Automatic Temperature Control system, not a manual HVAC control system, correct?

Specifically, you want to determine whether it's the power or ground (or both) to the blower motor you are missing when it should be running. That will help you determine if the issue is via the power side from the TIPM or via the switched ground side through the blower motor speed controller.

TIPMs are known to cause a lot of issues, although I can't say I've ever heard of a faulty TIPM causing this specific issue. But, if you confirm you don't have +12V to the blower (Dk Blue/Yellow tracer wire) when you think you should, then confirm it's also not present at the TIPM Dk Blue wire at pin 25, then confirm the fuse is good, that is a pretty good sign the TIPM is the issue. But if you have power but the blower isn't running, provide ground and the motor runs (to confirm it's not corrosion in a connector or something that makes contact when warm), that would send you down the path of an issue with the blower module first, then the A/C Heater control.

-Rod

 

Yes there were various reasons. However this issue was present before as well. The flash tsb was only found as a result of searching for solutions. It did fix some temperature swing issues, but not the fan speed.
I appreciate the explaination as it gives me more direction than I have had from anyone or any resource. Thank you.
I will check and report back. (May be a little bit before I get to look at it.)

Novice question, but where is the TIPM located to find that connector?

Thank you again for the direction!

 

TIPM Totally integrated power module. It's under the hood. Fuses and relays and such. Not my favorite design.