HVAC Blower issues

[8thNote]

Whenever I get a new-to-me gmt400, I just go ahead and replace the blower motor and the resistor. It's a very easy job and you can get both for less than $50 brand new. And while youve got the blower motor/fan out, don't forget to shop vac the evaporator then spray it with some foaming AC coil cleaner.

Now that I'm past 40, a cold ac that blows hard is a must.

 

[Reluctanse]

Replaced the blower, replaced the resistor, all working. Thanks for the input fellas/fellettes/

 

[Reluctanse]

Jumped in the truck today and the issue persists. No fan on any speed. What else could be causing this??

 

[Reluctanse]

Replaced the relay too now, it’s “working” again now. Hopefully that was it officially finally now lol… I guess we’ll see..

 

[bluex]

Fan speed switch or its connector....

 

[Reluctanse]

i'm getting more baffled. the intermittent issue persists.

i don't believe it to be the control module or the wiring there, i swapped it with the same issue, and the connector looks good... i can hear the fan relay clicking on/off when i turn it to high. so it's getting some signal.

i think there's a loose wire *somewhere* between the relay, the resistor, and the motor itself. unless there's some other connector in there I just don't see what else could cause this. I fussed around there and it's working again... for now...

 

[east302]

Going by memory here, but on my 98 I think there was an inline connector in the voltage line to the blower. It’s there, I assume, for ease of assembling the dash at the factory but mine had melted there. From the blower, it was maybe a foot up the wire? It’s something to look into if the connector at the blower switch is solid and not melted.