Welcome to Ultimate Subaru Message Board, my lurker friend!
|Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.
We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!
Serving the Subaru Community since May 18th, 1998!
Clock backlight dimming
Posted 30 November 2012 - 11:21 AM
Anyone else notice this? Anyone try to fix this?
Posted 30 November 2012 - 12:21 PM
Posted 01 December 2012 - 01:55 AM
However, once the engine warms up and idles normally, the alternator is charging normally. If I turn on the dome light, then hit the brakes, the dome light won't dim as much, or even at all.
So basically it seems like the alternator just isn't charging as much as it should be. I'm sure you already knew about this, but just throwing it out there. Not to mention that turn signals seem to take up a lot of power (my voltmeter goes up/down 2 volts or so each time the turn signal clicks). The only thing to really do is get a new alternator, preferably one that can deal with a lot more electrical demand.
As Cougar stated, do check the battery connections too. Corrosion can create electrical resistance (again, I'm sure you already know this), which would not allow the alternator to charge to the best of its abilities. I learned that the hard way. For 2-3 days, I thought my starter was bad because my car wouldn't start at all; it would only click. Then I decided to hit my positive battery terminal with a hammer, it knocked off some dried up acid, and my car started like normal. Good thing the starter is a pain in the behind to pull out, or else I probably would've unnecessarily spent $100 on a new one.
Posted 01 December 2012 - 02:50 AM
Posted 01 December 2012 - 11:18 AM
So I should mention that it's just the dash illumination (and not the cluster because I have digidash) that is dimming. The headlights don't dim at all. I have an EJ engine/alternator with ~50k miles so that should be fine. The battery is pretty new, no corrosion. I did check the fusable links a few months ago and they were all tight with no corrosion. Grounds are new as of a few months ago also.
I think I need to dig into the schematics to see what circuits are shared between these things.
So maybe if I ask a different way, does anyone have the trip computer that does NOT see backlight dimming (headlights on of course) with the blinker?
Posted 01 December 2012 - 11:44 AM
Posted 02 December 2012 - 05:41 PM
Fuse #10 goes to the blinker. Fuse #12 goes to the instruments. They share a common supply, the black wire from the ignition switch. Bypassing one or the other to the battery eliminates the dimming. That also means it's not a ground.
So that means something has some resistance in the circuit back to the battery. There's no voltage drop at the fusible link (the 1.25mm link to the white wire). From there to the ign switch has about a 0.4V drop. The ign switch itself is 0.15V. The black wire from the ign switch to the fuse panel is about 0.15V. So in total the drop from the fusible link is around 0.7V when the blinker lights are on, and about 0.4V with the blinker off.
Most of that drop is in the white wire. I don't think the ign switch is bad with a 0.15V drop, seems ok but probably would be better with a new one; even still that wouldn't fix all the voltage drop and the dimming. I suspect it's not just my car, but that's how they all are due to the drop in the wiring. Yeah I'm kinda picky, these little things bother me.
So how to fix it? It seems to me the easiest way would be to tie the instrument cluster power into one of the relays going to a headlight. This would power the instrument cluster through the black/white wire and not the white wire, but still switch off/on with the ignition switch. I'm not sure how to break the connection inside the fuse box to isolate fuse #12. Basically I want to connect the supply from fuse #8 to fuse #12.
Posted 02 December 2012 - 06:09 PM
Based on my highly scientific WAG (wild-rump roast-guess) I'd say moving the current to the other circuit will be fine. It's no more than 15A (the fuse #12 rating) and the I used the headlight relay with only one 15A fuse on it (the other one has two 15A fuses). The red fusible link is good for 50A total, and the headlights would draw only 11A, the other lights max 15A, so grand total is less than 41A.
Posted 02 December 2012 - 07:31 PM
Posted 02 December 2012 - 07:56 PM
See below, the black/yellow wire at B15 (middle right).
Posted 03 December 2012 - 03:26 PM
Posted 03 December 2012 - 04:58 PM
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users