HELP Heater Blower motor will not work on 3 or 4

[dmc-4625]

I noticed that my heater blower motor does not work on setting 3 or 4. Initially thought it was a fuse or switch. They all checked good! Then thought of the relays, they are also good. What I have determined is that there is no power going to the fan speed thermal trip (thermal circuit breaker). Where does the breaker physically get its power and where is it located? It appears when checking continuity the power shows a dead short to ground.
I need some guidance!
Ken Keplinger
DMC-4625

[seventy4burban]

Will this help?https://uploads.tapatalk-cdn.com/20250310/5d3c88386b693dfdddbbb3316968bd08.jpg

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[Bitsyncmaster]

I've not taken a harness apart but would guess the 12 volt power going to the blower breaker is a direct wire to the feed through bolt at the rear of the relay compartment. Can't remember if there is one ring terminal for all the brown wires or multiple ring terminals on that feed through. If multiple, I would guess the bolt is not tight and that blower terminal not making connection.

[dmc-4625]

Will this help?https://uploads.tapatalk-cdn.com/20250310/5d3c88386b693dfdddbbb3316968bd08.jpg

Sent from my Pixel 9 Pro XL using Tapatalk

Fantastic Diagram! Thank you!!

[dmc-4625]

I've not taken a harness apart but would guess the 12 volt power going to the blower breaker is a direct wire to the feed through bolt at the rear of the relay compartment. Can't remember if there is one ring terminal for all the brown wires or multiple ring terminals on that feed through. If multiple, I would guess the bolt is not tight and that blower terminal not making connection.

According to the diagram that Brian sent the circuit breaker that is suppose to be hot all the time. When I checked with my multi-meter it is shorted to ground. Do you know where the wire terminates?

[Bitsyncmaster]

According to the diagram that Brian sent the circuit breaker that is suppose to be hot all the time. When I checked with my multi-meter it is shorted to ground. Do you know where the wire terminates?

Pull the load wire off the breaker and then test if you get 12 volts on it. You need to remove wires to test if the breaker got grounded. The load side can be tested for ohms since the relays off float that side.