Hey All, I've searched the forums, and saw people with the same issue as myself but no resolutions posted.....Here's what up

I upgraded my HU last night in the car (removing negative ground wire first before i get flamed) and everything went very smoothly. After getting it reassembled, I went for a drive and noticed that the backlight for the HVAC controls and the clock are not lit any longer. I tried disconnecting the dimmer connection between the factory side and the new HU and still no luck. When the headlights are off it works, when they are on no worky.

I can't take it in as "under warranty" because it's expired on my 05. 60,000 miles :-( any advise would be helpful.

 

did you hack into the stock harness or use an aftermarket harness to do the install..?

 

used an aftermarket harness from Best Buy. [/quote]

 

Hm..... Interesting... does your gauge cluster lite up..?

 

Yeah. the guage cluster lights up no problem at all and dims properly. I saw this post

https://www.scionlife.com/forums/vie...ight=backlight

and tried contacting "Grymson" to see what happened but had not heard a reply yet. Anyone? it's not a fuse since it gets light when the headlights are off.

 

*Edit - Reread, nevermind my origional post

That is one wierd problem, sounds like some wiring is messed up

 

if the ac works check your fuses both inside and out for a burnout

 

I just figured out what did it on my car. Was going back over thr wiring with a fine tooth comb and didn't realize there were 2 ilumination leads on the toyota harness. 1 positive and 1 negative.... not playing close attention when wiring i presumed one was on the HU since i'd never seen 2 on a factory harness and wired them together. will check my fuse box in a few and see what i blew.

 

went through the fuses near the clutch and under the engine and was unable to find anything wrong...does anyone know which relays might control the back light for the hvac, i assume it would be different then the one for the instrument panel as that still works properly.

 

https://www.scionlife.com/tech/elect...rical_tc05.zip

Sticky at the top of this board, one of the PDF files has all of the relay locations.

Its called 020-031 relay location.

It shows you all the relays.

As to which relay... im not sure, and I dont have enough time at the moment to look through the electrical stuff.

I'll look tomorrow and see if I can find it for you, in the mean time that electrical stuff might help you.

Tomorrow

 

Okay, if I am reading this right, the interior lights for the guages and HVAC are linked to a combination meter, not a relay.

In the 082-085 illumination PDF you can see the junction on the second page called A/C control assembly and the white cable attached to it goes to a junction connector, the problem either lies with the junction connector there, or with the combination meter attached to it.

My guess is that its that combination meter, and I have no clue where this part is in the car, or where you could get it...

So, I think you'll have to go to the dealer to get this fixed.

*Edit - I thought more of the problem, in the same PDF file as above it could also be the combination switch that switches with the light control switch.

 

Still lost sadly enough, i really can't figure this one out

 

Really, the only way I can think for you to get this fixed is through the dealer. I dont know of how you will really be able to figure it out on your own. I doubt I could get it.

So, either the dealer, or just live with the problem, thats all I can think of.

 

Have u been able to fix the problem?? I'm having a similar issue with my car as well....