Digital climate control does not dim

[joey b]

Ever since I hooked up my aftermarket head unit the digital readout on my climate control does not dim with the dimmer switch. There is a 4 wire harness that is not connected to anything at all without the stock deck. Is it possible to make my climate control dim once again?

[turby]

Mine does the same thing. Couldn't tell you what causes it.

[digitaloutsider]

The dimmer for the ECC is located inside the factory HU on the Cutlasses. Don't ask me why, it's stupid. Shawn made his own dimmer thingamabob when he put an aftermarket deck in his car. You can try asking him if he can make you another one.

[turby]

My buddies 92 Buick Park Avenue Ultra does the same thing.

[GnatGoSplat]

Yup, I built me a dimmer thingamabob.

 

It consists of a 555 timer chip, a couple of resistors, capacitors, and a little trimpot used for fine tuning the brightness. All stuff you can (or could) get from Radio Shack.

 

They take awhile to build though, so I really don't have time to build them for others. I think I have a schematic somewhere I can post if someone is interested.

[Stevo]

I put a piece of window tint film over mine... it looks perfectly fine now, even brightens/dims with my dash proper.

[rockfangd]

the radio dimmer is what controls the climate control dimmer. just run the wire that used to dim the radio into the climate control module

[5speedz34]

the radio dimmer is what controls the climate control dimmer. just run the wire that used to dim the radio into the climate control module

 

You're kidding right?!!?!

[Psych0matt]

the radio dimmer is what controls the climate control dimmer. just run the wire that used to dim the radio into the climate control module

 

You're kidding right?!!?!

 

w3rd

[digitaloutsider]

the radio dimmer is what controls the climate control dimmer. just run the wire that used to dim the radio into the climate control module

 

You're kidding right?!!?!

 

It's seriously that simple? ROFL.

[Crazy K]

I have discovered a flaw on the 93 and 94 CS autoclimate control. they were made with a tinted window, and not a thick green plastic window like the 88-92's. the green plastic is similiar to what most of those two knob radios of the same era have to dampen the light form the display. The acc lens from a 88-92 can be extracted, and installed in the 93-94... giving it the exact correct color.

 

so those of you with non-dimming displays... Yes the radio is part of the probelm, but also the faded display tint on 93 and 94 models... and oh yes... they use the same exact plugs, the mounting is differnt so it would not be worthwhile to substitute and older unit.

[Psych0matt]

so...

 

 

is there a way to make it dim with this wire or not?

[GnatGoSplat]

so...

 

 

is there a way to make it dim with this wire or not?

 

No, I tried everything with my 89 before building a circuit.

Don't take my word for it though, I've been wrong before. I encourage you to try it and see.

[RJansen658]

rockfangd is right. When I put in the 3rd Gen radio, mine didnt dim at first either, and one plug wouldn't fit. The extra plug contained the dimming signal. It takes 2 wires to make it work properly, not just one, and not the gray wire. You can get the feeds you need from the headlight switch or the radio harness (but colors may be different at radio harness). The feeds you need are Dim Level and Dim Enable. One is brown/white and one is yellow. They are at the headlight switch of all W-Bodies. You can tell them apart by backprobing with a test light and turning the dimmer switch. The one that brightens and dims is the Dim Level feed. The gray wire is a completely different system than what the HVAC control uses on a lot of W-Bodies, not just the Cutlass. The gray wire is used by the interior lighting system, non digital clusters, some radios (which still relay the Dim Lvl and Dim Enable feeds gen1). I think all the digital cluster use the 2 wire system, my Regal UB3 used the 2 wire system.

[GnatGoSplat]

What do you do with the yellow Dim Enable wire?

Connecting BRN-WHT (VF Dimming Level) to the climate control's PPL-YEL wire (VF Dimming Input) results in the HVAC display going completely blank when the lights are turned on. At least that's the behavior in my '89.

 

[Psych0matt]

this needs to have a write up done if it actually works. Most people on here have aftermarket decks (well, a lot do anyways)

[GnatGoSplat]

So has anyone else been able to get rockfangd's method to work? Anyone? Anyone?

 

I really want to know if I designed and built that dimming circuit for nothing!