Display on the climate control not working

RON MCCOY

MEMBER
1999 BUICK REGAL
TURBO
225,000 MILES

We had a small electrical problem on the window portion underneath the seat and fixed it. I'm a technician and every connection was re-soldered. We have everything working but we do not have display on the climate control. I replaced it with a new unit and still do not have any display. Every connection and he has been checked as well as all contacts cleaned with an electronics cleaner. How can I obtain a power output for the Molex plug on the back connector? We bought a Chilton's manual but can't figure out voltages for this system.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,269 POSTS

Hi,

I attached the wiring schematic I have for automatic climate control. If you have manual control, let me know.

The first thing I question as a problem is a splice. There is a splice in the ignition power supply to the controller. I highlighted and circled it in pic 1. What I suggest is to first check the HVAC fuse in the fuse box. Make sure the fuse is good, tight, free of corrosion, and there is power to and from it. Here is a link to help:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If the fuse is good, then go to the controller and locate the brown wire (C5) and see if there is power to it when the key is in the run position.

I have a feeling there is an issue with that splice in the ignition power supply.

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below. Note: The schematic was two pages long. I had to cut each one in half to make them readable for you. However, I did overlap them so you can follow from one to the next. Additionally, I highlighted the wiring involved.

Images (Click to make bigger)