AC troubles!!

[Terry P]

Any help would be greatly appreciated!!Blower is working intermittently on my 2019 ram 1500 classic tradesman.Replaced fuse/relay and blower motor and nothing changed. Sometimes it works when you turn it on and sometimes it dont. Compressor kicks in as it should . Driving down the road it may kick on start working . As of yet it hasnt went off after it kicks on unless you kill the motor and then it might not start back. If your driving down the road and it starts working it isnt after a bump or anything it just kicks on and starts.

 

[Brandon-w]

That sounds to me like a broken wire or a bad connection somewhere. Metal heats up expands and pulls power away then cools and connects repeating the process. I'd start by pulling the wire off the blower motor resistor and seeing if there are any burnt spots or if the blade connectors opened up any. Hopefully it's something simple.

 

[Jeepwalker]

Same thing on the HIGH (mode) too?

 

[Travelin Ram]

Sometimes it’s worth paying for a professional diagnosis.

A good tech with a bidirectional scanner can see all the commands and responses between the switches, sensors, and the controlled device. And manipulate the system directly from the scanner.

They can find out more in 30 minutes than hours of tedious poking around with a test light or wiggling wires.

 

[Jeepwalker]

The "Ideal" thing to do would be to scan the truck's HVAC module for codes. But your truck (post 2018) requires a Secure Gateway Access device and most parts stores are not likely to have that. The dealer or if you know a buddy with high level scan tools, could do it. Then they could also turn on/off the fan via the scan tool and test it for operation.

You don't have a warranty for it, I take?

 

[16Ram4x4]

I would go with what Brandon-w has suggested and take a good look at the blower speed control resistor for burnt connections or a burnt spot on the resistor itself.
The other thing to check is your actual rotary switch to see it you have voltage at each of the fan speed settings as you could have a no connection at certain speeds.
On my 01 Dakota I went through two speed control resistors and one fan control switch in 12 years of ownership.