90 Q45 AC Control Panel Help??

[TwoGrim]

The AC control panel on my 90 Q45 has died, nothing works, no lights no fan nothing. I hate to invest in a new control unit if that is not the problem. I have checked and there are no blown fuses or loose connections. I don't know where else to look. I have read online regarding repairs to this unit, however they all indicate that the unit still works the display simply wont light up which is not my problem. Help!!! Any suggestions?

[maxnix]

Did you see the reference to http://www.jerrytucker.net ?

[TwoGrim]

Yes, but I thought he only repaired the display part of the control panel, not if the entire thing was dead. Am I wrong, (not the first probably not the last time!)

[911/Q45]

I think you're right about what Jerry Tucker repairs, but call him he's very willing to help.

[TwoGrim]

Well after a phone call to the specialist, I am more confused than ever, I am now thinking more than before that I am not getting any power to the AC control module. I have been told that with the key on I should hold the off button down and it would light up the unit and the fan should start (it did nothing). Anybody have any idea of how or what supplies power to the HVAC controls? I have ckd all the fuses and found nothing wrong, I am going to pull the dash apart tomorrow and ck to see if I have any power going into the unit, i expect that I am suposed to have at least two (one for lights and at least one main power).

[texasoil]

Did you check the fuses in the engine compartment just aft of the battery?

[TwoGrim]

Yes they all ck out fine.

[texasoil]

next step is to trace power supply using FSM diagrams. The wiring circuitry is far from simple. Easiest to start at the unit to see if power is getting ther-if so, thenunit is faulty. Unlikely, but possible.

[TwoGrim]

Any chance you might know which wires are supposed to have power to them?

I have been trying to get a copy of the wiring diagram for this car to no avail!

[texasoil]

post on the board. I think someone has the factory service manual available. It is not possible for me to explain the rat nest of stuff you will see.

[TwoGrim]

Thanks for all your help, I will have to keep looking.