Does anyone know where online you can find any pics of wiring for a 2003 duramax. Having heater issues and I'm pretty sure it's a connection issue, but can't find any books or info on wiring or heater components. Thanks.:cool:

Might explain your problem a little more.

One common problem these vehicles have is the fan speed resistor - it is under the main heater box where the passenger feet are. You have to remove the big cover to get access, you will see it attached with two screws. You may have to splice a new connection if yours is damaged.:)

Might explain your problem a little more.

One common problem these vehicles have is the fan speed resistor - it is under the main heater box where the passenger feet are. You have to remove the big cover to get access, you will see it attached with two screws. You may have to splice a new connection if yours is damaged.:)
Like he said, the blower related problems are 99% of the time related to failure of the blower resistor (common enough I stock them) and many failures are accompanied by the melting of the plug socket due to terminal tension loss and the heat associated with a now poor connection (again, common enough that I stock the connector).

The failure is manifested as the loss of one or more blower speeds. Even the High speed (5) can fail, which, technically is not routed through a resistor, but still passes thru the module that is the resistor assy.


SO................elaborate on your problem for diagnosis help, AND.......
I can't think of a link right now that gives the blower wiring diagrams, but I do have factory GM manuals ($225 thru my dealer, IIRC).

Mine has the dual climate control and it always blows hot air out the drivers side. I see the actuater but it has'nt got any wires plugged on it. I found a set of wires close by that has nothing plugged on it but it will not quite reach and it's not the right plug on the end.