Dash lights come on with brake lights & blinker???

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bulwnkl
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Dash lights come on with brake lights & blinker???

Postby bulwnkl » Tue Feb 19, 2008 8:47 am

OK, so yesterday I noticed that whenever I push on the brakes (specifically, when the brake lights come on) the dash lights turn on. The radio dims, the boost gauge lights up, and so do the instrument cluster lights.

This morning on the way to work, I see that it also happens in concert with the right-hand-only blinkers. So, the dash lights and radio backlight are blinking right along with the right-turn blinker.

I searched over at USMB last night and saw a couple-year-old thread with a similar problem but the O.P. never followed up. The recommendation there was that there was some sort of ground back-feed associated with a light bulb or socket. If that's so, then I'd say it's my right rear corner that's the trouble.

Has anyone ever had this happen? What did you do to fix it? If not, what do you suggest? I'll try to disassemble the RR taillight assy today and see what I see and what happens w/o that light plugged in. All input is appreciated!

bulwnkl
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Postby bulwnkl » Tue Feb 19, 2008 12:42 pm

Just checked other lights. The front corner/marker/blinker lights are definitely coming on dimly on the RF corner when I push the brakes as well. The LF is very hard to see in the sun, but it may be coming on very dimly as well. I'm going to post a follow-up at USMB as well to try to get some feedback there.

EDIT: Here is the USMB thread.[/url]

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Postby cliffhanger » Wed Feb 20, 2008 2:04 pm

good luck!
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Postby Hawk296 » Wed Feb 20, 2008 9:00 pm

So it sounds like every light that would normally light up when you turn the parking lights on is lighting up (including the radio dimming) when the brake lights or turn signals illuminate. Is that correct? Fuses are ok (Ive seen them backfeed in strange ways sometimes)? Have you changed anything recently like replacing light bulbs or anything? sounds like a strange problem!

bulwnkl
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Postby bulwnkl » Sun Feb 24, 2008 1:57 pm

Sorry it's taken me a few days to post back, guys. Hawk, yes that's basically the symptoms although the lights do not come on as brightly as they do when you just turn the markers/parks on.

The thought at USMB ran to a bulb shorting (but not necessarily burned out). I can't find such an issue (no bulb removals nor replacements eliminate the problem). I'm very suspicious of the very corroded wiring connector for trailer lights (extreme salt use here and no cover since it's that silly double-4-pin connector thingy U-Haul uses), or possibly even the convertor box itself. That's all U-Haul stuff and so should have a warranty left on it (installed last summer). I just haven't gotten it back to them yet.

One poster at USMB who, IME, absolutely knows his stuff (Gloyale) suggested the possibility of a diode failure. I'm hoping that's the case, but that the failed diode is in the U-Haul wiring convertor rather than the factory harness. If it's in the factory harness, I'm in for it because I HATE troubleshooting and repairing automotive wiring, even though I understand it fine.

I'll post again when I've been to U-Haul or otherwise figured it out.

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Postby kidjoe » Mon Feb 25, 2008 12:07 am

try unplugging the trailer hitch wiring harness just behind the passenger side rear wheel.

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Postby Zooom » Mon Feb 25, 2008 7:31 pm

kidjoe wrote:try unplugging the trailer hitch wiring harness just behind the passenger side rear wheel.


+1 on that....and I am guessing you don't have the Subaru harness in place from the factory out to 4 pin, just the generic splice in unit that U-Haul puts on with a hitch???

bulwnkl
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Postby bulwnkl » Tue Feb 26, 2008 6:40 pm

Yes, it's U-Haul wiring. They cut off the factory harness end when they installed their box (I had installed one previously but it was DOA. Long story short, that's why I took it to U-Haul). Though I know that many, many folks say you shouldn't use aftermarket converters for this wiring, to me that's a little strange because Subaru has to do the same thing as anyone else to make their wiring system adapt to standard trailer wiring.

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Postby kidjoe » Tue Feb 26, 2008 9:43 pm

Do you use the hitch that much? If not get rid of the uhaul wiring at the splice. Not that I'm a certified tech or anything but dollars to donuts that's where the problem is.

bulwnkl
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Postby bulwnkl » Tue Mar 04, 2008 9:49 pm

Sorry for my tardiness in replying. It's not like I use the hitch every day, but I use it regularly (except not in the winter) to tow the boat and sometimes the utility trailer and in any event, every time I use it I need the lights. I've been out of town and am leaving again tomorrow, so I've done nothing with it since I last posted.

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Postby Zooom » Wed Mar 05, 2008 4:10 pm

bulwnkl wrote:Yes, it's U-Haul wiring. They cut off the factory harness end when they installed their box (I had installed one previously but it was DOA. Long story short, that's why I took it to U-Haul). Though I know that many, many folks say you shouldn't use aftermarket converters for this wiring, to me that's a little strange because Subaru has to do the same thing as anyone else to make their wiring system adapt to standard trailer wiring.


actually the Subaru wiring harness came out to a standard 4 pin set-up...I have had no problems with using it to my trailer for my bikes!

bulwnkl
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Postby bulwnkl » Thu Mar 06, 2008 11:40 am

Zooom wrote:actually the Subaru wiring harness came out to a standard 4 pin set-up...I have had no problems with using it to my trailer for my bikes!


When you say "the Subaru wiring harness" you are talking about the wiring that comes with the Subaru hitch and ends up right there near the receiver, correct?

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mbaksic
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Postby mbaksic » Fri Mar 14, 2008 6:35 pm

Disconnect the trailer harness. I had this happen to my old Cherokee years ago. I had dropped my mother off to do some shopping and was sitting in the Cherokee. It was not runnin, but I had my foot on the brake pedal. In the chrome bumper of the car ahead of me I could see the parking lites were on. When I took my foot off of the brake pedal, the lites went out. Trailer wiring was all corroded, and the yellow and green wires were backfeeding into the ground circuit and liting up my parking lites.

Mike
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bulwnkl
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Postby bulwnkl » Sat Mar 15, 2008 6:19 pm

U-haul just replaced the whole convertor box and wiring today. Problem solved, but I don't know whether it was the convertor or the corroded wiring at the outlet.

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mbaksic
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Postby mbaksic » Sat Mar 15, 2008 8:12 pm

Prolly the wiring. Thats common anywhere you have salt on the roads.

Mike
Even though I work on Dodges, I don't own one.


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