I have a 1998 Blazer with Auto Temp A/c and Heat Controls, I have replaced blower motor, control head in the dash and body control module, blower will blow fresh air setting only, no fan speeds at all, checked every fuse etc. Wife was driving when it quit, she said it made a noise then quit. Cold A/c comes out of dash when dirving, but below even low blower speed. Can I hook blower motor up directly to battery with a variable speed switch without setting vehicle on fire. It.s 98 degrees today. Yikes

 

First off welcome!
Think we can find a better way then burning up your truck.
Any thing in particular that sent you in the direction of changing your BCM? Those do have to be flashed with your VIN and a passlock re-learn I believe.
The usual suspect on this is the blower motor resistor. The problem is the most often tell is only blows high but its in the proper circuit. Check your PM I'm going to send something if I can find it.

your pm is not enabled yet think you need 24hrs or something like that

 

Spittybays has probably got it. I had a grand Prix that had the same issue and it was a resistor

 

Is the resister built into the blower motor on a 98? I can't find mine and the fan only has high and won't shut off even when key is off. I have a switch hooked up to the blower to shut it off.

 

More Information for ACDELCO 1571991






Alternate/OEM Part Number(s): 15094285, 15652873

 

Resistor is built into the controls I thought with Auto Air, also what is PM. I am new to this. Maybe it wasn't the body control module, if it was I did not have it flashed. Facing the blower motor it mounts to the right of the blower and the plug from it plugs into blower motor. I changed everything I could find. Thanks for reply spittybays

 

Yea that's the resistor you changed not the BCM. That just plugs in. PM is private message. You will see it up in the right corner when you sign in. Just searching for a link that might be relevant to a wire I had burn out, I also changed the resistor with no luck. The burned wire I had was. When I find it I send it and post it up on the board.

https://blazerforum.com/forum/lighti...id-pics-80107/