Hey guys I have a question for you regarding my digital climate control head unit on my 88 GTA with a digital dash.

Last year the climate control operated properly, but every so often the fan would cut out and the amber light indicating the fan speed would fade away to nothing. The weird part was that every other part of the climate control head unit was functioning properly and you could here the ducts change whenever moving to heater/vent. Now this didn't always happen, just while I was driving around [smooth paved roads] and usaully I just keep on pressing the fan speed buttons and it would usaully come back to life, but it kept on getting worse and occuring more frequently.

Currently the is no response from the fan and there are no amber lights on the fan speed indicator, although the climate control is operating properly. I have tried hot wiring the fan and it spins like crazy. I have replaced the fan relay and the transistor. Today I pulled the head unit out [harness' still attached with key on] and with a test light probed the harness'. There is power going into the head unit's man harness, but there is no power either coming in nor coming out of the harness connected directly to the fan speed control area of the head unit.

I guess the question I ask is whether or not I need a new head unit or is there another way I can go about this?

 

Tonight for some reason the fan control decided to work, except when you pushed the button to go to the high fan setting, the amber light goes out and the fan cuts off immediately. I can push the fan speed button lower and the amber light and fan both come back on.

This is a weird problem, can anyone help?

 

Try replacing the high speed blower motor relay.

 

When the fan speed control on my GM cars goes bad (4 speed settings, but with the manual switch) it usually ends up being the switch itself and a wiring harness that connects to that switch.

Admittedly, this is a different system than yours, but if the basic problem is the same as yours is experiencing you can diagnose it pretty easy. Go up under the hood to the fan relay and rap it with the handle of a screwdriver WHILE you are experiencing problems. If it immediately turns the fan on, but you know the relay itself is good (becuase you've replaced it) then it's the switch/wiring under the dash.