HVAC LED Fuse?

[Aladdin_Vein]

Does anybody know which fuse is responsible for the backlight LEDs on my ComforTemp HVAC control unit? Think I shorted something out when installing a new stereo and now none of the green LEDs are lighting up. Inspected all fuses visually but didn't notice anything out of the ordinary.

Any help would be much appreciated. Thanks!

 

[Spriteman]

What year is your car? Custom or limited?

 

[Aladdin_Vein]

What year is your car? Custom or limited?

Oops that would probably help eh. It's a 2001 Limited.

Also while I haven't verified this yet it seems like the memory of the HVAC unit is tied into this mystery fuse as well. I bought a circuit tester but it only seems to work on some of the fuses. Turning the ignition on changes which fuses work but some never do, regardless of if the ignition is on or off.

 

[Spriteman]

The lights reside in the HVAC Control Module but they are connected to the interior lighting system - that's how they're dimmed with the rest of the cluster lights.

The fuse for the HVAC control module is the IGN 3 Fuse 10 amp on the rear fuse block.

And the lighting portion of the equation is fused at DIMR Fuse 14 10 amp also in the rear fuse block.

There are a few other components that could be at issue including Dash Integration Module DIM and the PRK Lamp Relay.

Let us know what you find.

PS - If you would like the full diagrams just PM me with your email and I'll forward them over.

 

[Aladdin_Vein]

Thanks a lot man. Tried swapping both those fuses out with the spare and didn't notice a difference. I'm going to try picking up a new relay on my way to work today and we'll see if that does it. Hoping it's not the DIM as that sounds like that might be a bit of a chore to access. Will let you know how it goes with the relay. Thanks again!

 

[Aladdin_Vein]

Replaced the PRK relay (44) as well, no luck. Any ideas what I should try next? Debating buying a multimeter and going through all the fuses again.

 

[Aladdin_Vein]

Went through every fuse with a multimeter and they all seemed fine. Anybody out there got any other ideas? The orange LED's on the HVAC control unit work, just not the green ones.

Maybe taking it to a shop with a tech ii would help figure out what it is?

 

[Spriteman]

I've read in other posts of guys removing the control head and resoldering some of the solder lines on the back of the unit.

This applies to the instrument cluster as well.

When you use the dimmer switch do the cluster lights and the orange lights go up and down in intensity?

This should tell you if you're dimmer function is working and rule that out as a point of failure.

If you decide to change out the control head you might try finding a used one at a salvage yard - also there are shops on the internet that offer a repair service for electronic components. A few of the members here have used them for different parts and have come away with good reports.

 

[Aladdin_Vein]

I don't actually have the dimmer switch hooked up at the moment; I removed it when I took the dash apart and then disassembled it in the hopes of lubricating the plastic parking light button which was always sticking. Unfortunately I completely destroyed the unit in the process and had to order another one. I'll let you know how I make out with the new one when it arrives. It sounds like you're thinking it's likely the control unit itself though and not something caused by a fuse or the computer system?

I'm considering replacing in the LEDs in the car over the next while as a lot of them are burning out but I'm not sure how much faith I have in my soldering skills as I'm just learning. Probably will start with one of the less expensive/easier-to-work on components and go from there haha.

Thanks for your help Sprite. As a rule I'm not very good with anything electrical and the crazy computer system that seems to be connected to everything in these cars makes it that much more confusing. Have a good weekend!