LED on heater control does not always go off

ROB CATLIN

MEMBER
1990 CHEVROLET SILVERADO
184,000 MILES

When I turn the ignition off the LED on the heater/AC stays on. Sometimes with some of the LED display. Now and then I can press a control on off or A/C until I hear click under the dash then turn the key back off and it goes off. Sometimes I can just turn the key on and off until it goes off. Could this be a relay or the main control? I think this could be part of my battery drain issue I have also.

Saturday, December 21st, 2019 AT 7:38 AM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,101 POSTS

Hi,

When this happens, are there any other lights affected or is it only the HVAC control display?

I attached a picture below (pic 1) that shows all interior panels illumination. The second pic shows relays related to the unit. I have never experienced this type of issue, but lets give it a try. First, locate the relays related to the HVAC. Next, since you hear a clicking, it does sound like a relay, so see if you can feel the click from one of the relays indicated.

Let me know what you find.

Joe

Images (Click to make bigger)