Hi guys,
I'm new to the group! I'm currently fixing up my '98 Jimmy GMC into a bit of a on the road camper for my hiking expeditions. I know not technically a Blazer buuuut close enough. Haha!

We've done a bit so far; fuel filter, fuel pump, spark plugs, blower motor, mirrors, lights and stereo.

I know it's a small thing but it drives me absolutely nuts that my fan controls only half work. 1 and 2 don't blow any air, 3 and 4 work great. I'm not the best at diagnostics and I haven't found any information online. Does anyone have any idea what it could be? Is there any relation to that problem and my AC not working? I would assume it's two different issues though.

Thanks!

 

Same with my 02. I keep meaning to take it apart and try to figure out what’s going on, but never get around to it

 

That's either going to be the blower selector switch in the dash, the resistor network or the wiring between them. Do you have and no how to use a digital multimeter?


George

 

Hm, I've seen people use them but I don't have a great understanding of them though. They're used to find power, right? I can easily switch out the fan switch but it seems weird that only half of it would be broken or?

 

There are two ways to go on issues like this:

1. Proper diagnosis before a targeted repair or replacement. This is how I usually roll because I am not a fan of the parts cannon. If you get a digital multi meter and want to learn, I can help
2. Take a good guess and replace parts. This may or my not work because sometimes its the wiring and not parts, especially on an older truck. If you want to go this route, the easiest start is the resistor network.