99 SSEi,

My climate control shows --- when I start up the car. Sometimes it lasts for 5-10 minutes before hearing a relay click near the glovebox, and then it will work properly again.

Anyone know what the cause might be?

thanks

The air mix actuator is behind the glove box. Take out the glove box liner and then start the car. Watch what it does. Is it sticking or hanging on something?

Hi Matt,

When the display reads --- what functions work and what does not?
Also you said your here a relay click then things work normally; when did this all begin to happen? Have you disconnected the car battery lately?

Hi,
When it shows ---, no buttons at all work on the climate control. When I hear the click everything works.
Yes I did disconnect the battery for a couple days a couple months ago, trying to reset the security light. I know my battery needs replacement - battery tester reports low voltage when car is off.

Matt do me a favor and check out this posting https://www.gmforum.com/specifications-general-information-132/1998-service-manual-283419/

It contains factory service manual information on your car. It'* for a 1998 SSEi but covers your car as well

I'll do some digging to, because I know I read in there what exactly your going through and how to trouble shoot it to fix the problem.