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Working on sons trailblazer. All blower motor speeds work except high position 5. Checked 40 amp fuse in distribution center number 35. Has current one one side in panel dead on other. Anyone have a schematic of the power distribution center so I can see where both side of fuse go to so I can diagnosis it
With fuse out and you take test light on both terminals in distribution center one terminal in center is hot other one no voltage and I believe it's fuse number 35
With the fuse removed, you mentioned that one terminal has power, but the second terminal does not. That is normal. When the fuse is installed (one that is not blown), the fuse bridges the power from one terminal to the other. You can do a quick & dirty fuse check by swapping it with a similar one that's in the power distribution box. Without getting too wordy, speed setting 5 provides power to the the Blower Motor Relay, activates the relay, and relay then allows full power from Fuse 35 (40A) to flow directly to the blower motor. As Cheryl stated, it's very likely a blown fuse. If you replace it and blows again, you will have to dig deeper.
I've attached a wiring diagram.
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Last edit: 3 years 1 week ago by jm_460. Reason: Added correct files and correction
Chevyman wrote: Working on sons trailblazer. All blower motor speeds work except high position 5. Checked 40 amp fuse in distribution center number 35. Has current one one side in panel dead on other. Anyone have a schematic of the power distribution center so I can see where both side of fuse go to so I can diagnosis it
The fuse that is blown, on the side that doesn’t light, go B- and touch it to the terminal. If it lights there’s a path to ground.
Making Pressure Differential Sensors (PDA Sensors) for pressure pulse diagnostics.
Currently servicing Central Texas.
