HVAC Control Issue

[Rebel25A]

Ok I thought I was smart...but obviously not...my New to me 2001 Bonneville SSEi has an issue with the HVAC controls...the backlights on the knobs are lit but I have no digital display in the center and nothing I do changes the A/C (which is on) from floor...no blower speed adjustment or anything...HELP!!!...I bought a used control and it is the same when installed

[bobgto65]

Ouch... this sounds like a bad electrical connection.
Start by checking fuse 34 in the rear fuse block.
Then check the grounds at connectors A1 and A5 at the HVAC module, they are black/white and black
Check the connector at the IPM as that data signal comes from there
The yellow wire to the HVAC module is for backlights so check the voltage with the lights on.
If you cant find anything wrong, you may have to replace the IPM as that is what controls all the actuators.

[Rebel25A]

Where is the IPM...previous owner said he was told it was bad...I will check the things you listed...Thanks for the response