Fan Doesn't Work Right - HELP!

[steff]

I've already done a search on the forum and come up empty handed, so here goes . . .

My fan will only work on speeds 3 and 4, speeds 1 and 2 won't work at all.

To see if it was the switch or the motor I unplugged the wiring harness from my fan under the hood and hooked it up to a used Blazer fan motor - same problem. So I figured it was a no brainer, it must be the switch. So I replaced the switch with a new one and my fan still doesn't work on speeds 1 and 2.

Could my motor AND the test motor be bad? Is there anything else that could go bad between the switch and the motor? Please help!

Thanks!

[tom3]

Somewhere there is a resistor pack that reduces the voltage to the blower motor. These are noted for troubles like this. It's a 20 dollar part and, depending on year, is usually under the hood, on the AC/heater box on passenger side top. Look for a smaller bolt in plate with a 3 or 4 wire connector.

[BlazerLT]

Yip, Tom3 is right.