JakeVRich

I want to start this off by saying I haven't seen my exact issue posted anywhere, so I'm giving it a shot.

I just bought my first truck. Its a 2004 2500HD 6.0. The guy I bought it from had the blower motor resistor pulled out and basically had a switch set up to just turn the blower on full blast.

The AC worked fine like this, but the wires he had hooked up were getting really hot (I'm assuming because the resistor was cut out). I bought a new resistor and wired everything back up. The AC controls work now, and I'm able to change the speed of the blower.

My issue is that when I turn the ignition off, the blower continues to blow for about 5 seconds and then finally turns off. I don't FEEL like this is an issue, but wanted to see if anybody has had anything similar happen.

I was thinking maybe a bad relay? Or maybe with the aftermarket resistor, the blower just continues to get power for a few seconds after ignition off?

Thanks in advance for any help or insight anyone has!

jfmorris

I am looking at an electrical diagram on https://charm.li - and on the GMT800 series (I have a 2006 Silverado), there is no separate blower relay under the hood like there is on my older 1996 GMT400 truck. Instead, they built the relay into the Blower Motor Resistor Assembly, which you just replaced. The power runs from the battery, through a 40A blower fuse in the box under the hood, and straight to that resistor assembly which has the relay in it. Control of the relay and resistor assembly comes from the HVAC control module in the dash - i.e. the module where your blower switch is located. Power to THAT module is interrupted by the ignition circuit, but power to the resistor assembly is not.

I've not noticed, but I've been driving that 2006 Silverado work truck for about 10 years, and do not THINK that the blower runs after I take the key out. But the radio does, until I open the door.

If everything else is working well, I would not worry over much about it, but I'll report back here this afternoon on whether my truck does this.