Both turn signal flash

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Jul 12, 2005 | 09:25 PM

Mecheng

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Joined: Mar 2004

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From: St Louis, Mo

Both turn signal flash

I have an 85 F-150 truck. It's been so reliable for many years. Recently I have experienced a problem with the right hand turn signal. When I turn it on the right signals flash and so the left ones (front and back) but much dimmer. I replaced the turn signal switch and it did not change a thing. Also the warning buzzer sounds to the blinking of the right turn signal only. I have done no mods to the wiring. I do have nasty corroded looking trailer harness though. Oh, I did have problem with the stop light switch and replaced it with and Advance Auto part. This seems to be about the time I noticed the turn signal problem.

Just finished a firing up my 302HO transplant and very anixous to get the truck back on the road.

Jul 13, 2005 | 12:08 AM

minishtr

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Could be the switch or when you replaced it you moved some bad wires around.Check the wiring and the trailer plug.

Jul 13, 2005 | 01:16 AM

220k-f-150

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Check grounds, sounds like its using other light to ground out. Check that trailer harness too.

Check those bulbs and sockets too. Front and back for corrsion bad wire and such.

Last edited by 220k-f-150; Jul 13, 2005 at 01:31 AM.

Jul 13, 2005 | 06:47 AM

Mecheng

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Joined: Mar 2004

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From: St Louis, Mo

Yep, now that I found the color coded wiring diagram I think I will start with turn signal multifunction switch. I will disconnect the left hand blinker wires at the connector under the dash from the turn signal switch and determine if this "current leakage" is at the switch or downstream. It's a new Wells switch too. I'd be surprised if it's bad but who knows.

Jul 13, 2005 | 09:48 AM

cokeman

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It's definitely a grounding problem. Before you spend too much time testing the switch, take 220k's advice and check all the grounds first.

Jul 13, 2005 | 11:06 AM

stuart1

Cargo Master

Joined: Jun 2003

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From: Somewhere Saskatchewan

Have a good look at the bulbs. They are double filament and if one breaks it can fall onto the other one and cause a feed back.

Jul 13, 2005 | 11:41 AM

Franklin2

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From: Virginia

I too vote a grounding problem. I would also fix the obvious trailer wiring problem. All your signals go there to, so it could get crossed up if it's in really bad shape. If you do not have time to repair it, just cut it out and tape the wires off till you get a chance to put a new one on.