Rear signal and brake lights dim front flash fast
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Rear signal and brake lights dim front flash fast
Rear signal lights dim and front signals flash fast when the brake is applied. Also the dome lights dim and brighten as the signal flashes. Anyone else ever have this problem? There seems to be a short to ground but I'm not blowing any fuses. Any ideas?
Lead Driver
Joined: Oct 2010
Posts: 5,420
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From: Ouray, CO
The filament acts like a resister and will (often) protect a fuse by limiting the current.
You have a fun isolation task ahead
What happens when you turn on the 4-way hazards?
Try with Left and right turn signals to (hopefully) identify which SIDE the problem is on.
* with parking lights on
* with parking lights OFF
* with headlights ON
* with high-beams ON
with ALL lights OFF, put something on the brakes, try left, right turn signals - and then with 4-way hazard, hopefully they behave differently.
The BRAKES will help ID if the problem is FRONT or BACK, if the problem is the same WITH brakes - it's the back, if it DOESN'T repeat with brakes it's FRONT.
Depending on the model year, you may be able to swap the flasher with the 4-way (or another one) to rule out the flasher. Typically, the flasher is easy/cheap and having a spare (if you buy 1 but don't need it) isn't a big deal.
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I think I'm past what your suggesting at this point. I've been through every bulb on the truck. No loose or dangling filaments. I disconnected the wiring harness below the master cylinder and I no longer have the short to ground in the rear of the truck. I suspect it may be a wire on the harness on the tilt column. Stay tuned.
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Joined: Jan 2006
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From: Gary, IN
Do your front signals work for intended side? I had the same issue when I broke a ground changing my fuel pump. There is a ground on the harness driver side rear on the frame rail. My lights were dim, fast flash when brake pedal pressed, and signals worked for opposite sides in front.
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Yes everything works normal until I step on the brake. I have been over every ground on the truck because that's what it acted like. Here's what makes it tough. It doesn't do it all the time. I haven't had a chance to work on it further so I will let you know how I make out.
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