Just to clarify your post is it the lights that don't work, or the switches?
2003 GMC Sierra Control Panel Issues
Fan works great but have lost inside/outside air switch, AC switch, and rear defogger with no LED lights. All circuit breakers, relays etc. test ok. Bought a new control panel, plugged it in.....same issue. Could be original panel failed and replacement (new model 599-210xd from Dorman) is also bad out of the box, but what are the chances? Any ideas as I really don't want to pull wire harness if I don't have to.
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So you have no power at all to the control unit.
I'd be looking for a blown fuse.
I'd be looking for a blown fuse.
Yep, I read what you said in the previous post.As I said in my first post, all circuit fuses and relays tested good (every fuse in truck tested by myself and 2 electricians).
The fan uses separate fuses (one if it automatic, 2 if it's manual speed selection).
All that proves is that the fan fuses are good.
Yes, it could be a wiring problem.
I agree it isn't the control unit.
Good luck
I've got some control unit drawings, nothing for the 2003; but the main wires should be the same, I'll dig them out tonight
Jack, the manual control unit uses 4 fuses, 2 are for the blower motor.
The automatic control unit uses 3 fuses, 1 is for the blower motor.
The 2 remaining fuses are the same for either unit.
There is an orange that is labeled battery.
And a brown that is labeled IGN 3
Both of those circuits are hot when in key on.
The automatic control unit uses 3 fuses, 1 is for the blower motor.
The 2 remaining fuses are the same for either unit.
There is an orange that is labeled battery.
And a brown that is labeled IGN 3
Both of those circuits are hot when in key on.
Jack, they might share a ground; but I see no reason to share a fuse
Jack, the drawings that I have only show the wiring connections to the unit in the dash.
They are named and they have colours, I don't recall if the pin numbers are there.
I can check for you; but home at the moment, will do shortly
They are named and they have colours, I don't recall if the pin numbers are there.
I can check for you; but home at the moment, will do shortly
Jack, bare wire shorts could cause transistors to pop.
Hard to say what kind of damage you may have.
I suspect new modules may require programing.
The engine size, the transmission type, etc needs to be the same and it may require that the serial number be correct.
Hard to say what kind of damage you may have.
I suspect new modules may require programing.
The engine size, the transmission type, etc needs to be the same and it may require that the serial number be correct.
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