Illumination Control

As promised, I installed my stereo this weekend - all but the speakers, which I hope to install next weekend.

 

The system is - Alpine HU with iPod control in AVO dash console, 4 channel Rcokford amp under the passenger seat, crossovers for JL VR610 splits in dashboard behind stereo, RF sub in a box in the boot and ipod in glovebox.

 

I took photos at each step, as I plan to post as much info as possible - to pay back (or pay forward) all the help Ive garnered from this forum. The head unit looks great - the grey in it suits the dash colour, the leds are a close match for the Subaru HU and ACC displays, and there are a few red lights to really link it in visually at night. Here is a teaser photo . .

 

The purpose of this post is to ask about ilumination control. I should have thought about this before screwing the unit in, so I'm only going off the pin connector info in other threads on this site.

 

In Oz, we have a "bright" switch under the cubby that changes the dash ilumination from dim to bright and vice versa. I haven't notice this in photos of US models, so I wonder if it is made redundant by DLR.

 

Anyways, I connected the standard ilum pin to the Alpine HU. It only dims with the headlights, but the standard HU dimmed and brightened with the bright button as well. How does the standard HU get both these triggers? Does my install not demonstrate that the bright switch is affecting it in some other way? Is there another pin that triggers with the bright switch? Should I be trying to run a trigger straight from the bright switch? Or some kind of realy?

 

As I drive with my lights on during the day, on sunny days, I can't read the information on the dash unless I push the bright button. With the dash dimmed, the stero looks to bright. I think it would really enhance the integration of this unit if I could make it replicate the dimming logic of the standard unit.

 

Any ideas?

Okay, so the photo didn't work. Sorry - I'll try to figure that out later

Can't wait for the updates.

Okay, so the photo didn't work. Sorry - I'll try to figure that out later

You can't image link from your hard drive. You need to host it on another site to do that, or you can make it an attatchment here. Scroll down under the reply box (don't use 'quick reply') and you'll see "Attatch files with a Manage Attatchments button". You can pull one from your HD that way.

Okay, I'll try that. Thanks for the advice.

 

Now, any ideas on the ilumination?

US cars do have the bright switch -- it's part of the clock/mpg display in 05-06 models.

 

My best guess is that the "bright" switch bypasses the dimmer's variable ground circuit and provides the stock unit with full ground, which equals full illumination. The aftermarket units just check for the presence of +12v on the illumination wire and if it is there, the unit dims. This would explain why an aftermarket unit would remain dimmed while the stock unit would be at full brightness.

 

Old Kenwood units (early 1990s) did use the factory illumination + and - for perfect dimmer integration.

So, John, if i understand right - in simple terms - you're saying that the std ilum input transmits 0, 0.5 or 1, but my stereo really only figures 0 an 1?

 

If I understand that right, then if I investigate the voltage accross that pin, I might be ale to come up with a relay or something?

See the information about the Illumination/Dimmer pins in post #2 of this thread: Stock head unit information -- pin-outs, subwoofer, aux inputs, and more.

 

What John M means by the "variable ground circuit" is the voltage that you see on the "Illumination -" wire, pin 7.

 

[Edited to add:] It's not really a "ground," since the voltage varies. It's just the lower-voltage side of what gets connected to the illumination light bulbs. Pin 1 is the "high" side.

 

I haven't been able test on a car with the "bright" switch, but I agree with John -- it's almost certainly altering the voltage on pin 7.

 

If you get a chance to measure the voltages on both pins 1 and 7 for various combinations of lights on/off, dash illumination dimmer settings, and "bright" switch on/off, I would be very interested to see what you find out.

BTW, when you installed your Alpine, did you use a wiring adaptor ("forward" harness)? if so, you're probably going to find that it did not include a wire on pin 7. Let me know if that's the case -- I may be able to help with that.

I wasn't sure how Subaru did their dimming. Most cars use +12v on the illumination wire and then vary the ground's resistance to change the amount of dimming. The +12v feed comes directly from the tail light circuit.

 

I guess Subaru could vary the input voltage and the illumination ground is either yes/no (0 or 1).

Interesting thoughts. I took to it with a multimeter on the weekend, but couldn't get a result.

 

I tried both pins - the dimmer one changed voltage with the roller dimmer switch down near the steering column. The other one just saw 12v when the headlights were turned on. Neither showed a change in voltage with the bright switch.

 

I'm starting to think John M is going to win the prize on this one. I tried to measure for changes in current, but the mulitmeter I was using didn't have the right range to notice any change in amperage. Maybe I should have been looking for a change in resistance. If I can get to it - I'll try measuring that.

 

SVXdc, I am using a forward harness. It doesn't have the dimmer pin, but at the moment that's not bothering me. When I figure out how to make the ilum dim with the bright switch, I'll then figure out how to make use of the dimmer pin.

 

By the way, I figured out that if you disconnect the bright switch, it never dims when you turn the lights on. I was going to just do this, but my girlfriend (read: vehicle co-owner) doesn't like the idea of driving down a country road at night being unable to dim the dashboard lights.

 

I'll post something when I've checked the resistance on the circuit. So maybe all the bright switch is doing is putting a resistor in the ciscuit and taking it out again. Stay tuned . . .

I tried both pins - the dimmer one changed voltage with the roller dimmer switch down near the steering column. The other one just saw 12v when the headlights were turned on.

That's consistent with other Subarus.

 

Let's back up just for a moment...

... the standard HU dimmed and brightened with the bright button as well. ...

Are you certain the stock HU did that too, not just the dash? Can you elaborate on how the various parts of the stock HU's display changed with the bright button in combination with different settings on the roller dimmer switch?

 

The SVX actually has a bright button also. But the radio harness has a third "dimmer" wire that reflects the mode of the bright button. The radio and dash do a somewhat complicated change -- some lights get brighter, and others get dimmer when you're in "daylight" (bright) vs. night (non-bright) mode.

 

There are no additional slots on the 14-pin radio harness that could be used for the bright function. So the car must be doing something more complicated on the two existing pins (1 and 7). Otherwise the bright mode signal would have to be reaching the stock HU via another harness.

I'm trying to figure out a way to get my bright button back after replacing the standard cubby hole & clock with the satnav unit.

 

Now when I drive during the daytime with the headlights on, I can't brighten up the dash anymore which makes it difficult to read.

 

I found this wiring diagram of the cubby hole clock, notice the Bright button is actually connected to some sort of micro processor!

 

Any ideas???

 

http://files.l33t.net.au/clockunit.jpg

When I was trying to figure out how the weird-arse illumination system, I noticed that when I unplugged the bright button, it never dimmed - it stayed bright. X-Lead . . can you make this happen? Have you got the bright button disconnected now with the new cubby unit? My research would have had me beleive that if you never plugged the bright switch back in, it would always stay bright.

Well I assume that its already disconnected since that particular unit (clock module) isn't there anymore.

 

Perhaps it connects into the back of the Nav screen somewhere?

 

I'll have a look this afternoon

wow all of these years installing aftermarket radios and i never hook up the illumination wire? i prefer my head unit to be at full brightness all the time, but i guess thats just me.

OK so I pulled the dash apart today, and found that the connector which normally attaches to the Clock unit is connected to part of the wiring harness and feeds into the GPS/DVD under the drivers seat.

 

When I disconnect it, the screen displays 'Communication Error' and the dash will still dim when the headlights are activated.

Scrap that, it was the wrong connector.

 

Anyway the usual Clock connector was in fact disconnected already, and yet the dash would still dim when the headlights were turned on.

 

However I do still have my original clock unit/cubby hole from the upgrade, so I attached it temporarily and found that by pressing the Bright button and then disconnecting the clock unit - the car would remember this setting and no longer dim the dash lights indefinately!

Well, that makes sense. So whichever mode you want it in, that's the mode you should disconnect it in!

I had an Alpine installed last Saturday and my oem radio lights/HVAC dont show up.

 

I bought a used forward and reverse harness from the For Sale formums for them to hook up, so I take it they didnt hook up BOTH the + and the - Illumination wire right??

anyone?

I had an Alpine installed last Saturday and my oem radio lights/HVAC dont show up.

 

I bought a used forward and reverse harness from the For Sale formums for them to hook up, so I take it they didnt hook up BOTH the + and the - Illumination wire right??

That's a pretty good bet. It's likely the harnesses don't have the Orange/White wire at pin 7. But you should look to be sure.

 

If the harnesses are missing those wires, e-mail me and I can help.

 

If those wires are present (and wired together) then something else is wrong.