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73-87 Chevy _ GMC Trucks => Electrical => Topic started by: Frankgomez1965 on May 08, 2017, 10:05:21 am

Title: Having problems with hazard or brake lights always staying on
Post by: Frankgomez1965 on May 08, 2017, 10:05:21 am
Hi every1 I'm working a 77 k10 an my hazard light or brake lights always stay on with ignition on or off. I've changed both signal flasher,  colum harness an checked all wiring. Turn signals work, brakes lights an back up lights all work. If some could help me out with this problem it would be great thanks.
Title: Re: Having problems with hazard lights always staying on
Post by: bd on May 08, 2017, 07:22:38 pm
How can you tell that the turn signals work if the hazard flashers are always on?  Is the hazard flasher button on the column depressed?
Title: Re: Having problems with hazard lights always staying on
Post by: Frankgomez1965 on May 09, 2017, 02:50:44 pm
My blinkers blink when on turn  the signal
Light on. 
Title: Re: Having problems with hazard lights always staying on
Post by: Frankgomez1965 on May 09, 2017, 02:53:10 pm
Or maybe it's my blinker staying on. Idk. It blinks when turn signal light on.
Title: Re: Having problems with hazard lights always staying on
Post by: bd on May 09, 2017, 03:20:22 pm
I'll try to assist, but I need you to answer a series of questions.  Do the lights flash with the ignition switched off?
Title: Re: Having problems with hazard lights always staying on
Post by: Frankgomez1965 on May 09, 2017, 11:43:28 pm
Nope lights stay on all the time. I messed with it some more today an I think it's the brake lights staying on not the hazard lights? I got this truck like this already. Put a battery in it an tail light stay on all time. Press on brake pedal nothing happens. Turn hazard light on an it just lights up on dash but don't blink.  I disconnect brake switch an they still stay on, i checked brake switch connector an there power on both side of connect when it's disconnected from switch. I don't. 😒
Title: Re: Having problems with hazard or brake lights always staying on
Post by: bd on May 10, 2017, 09:14:33 am
Do the rear lights remain on when you unplug the turn signal switch?
Title: Re: Having problems with hazard or brake lights always staying on
Post by: Frankgomez1965 on May 10, 2017, 09:54:14 am
I think they go off but I would have to double check later when I get home from work.
Title: Re: Having problems with hazard or brake lights always staying on
Post by: bd on May 10, 2017, 10:16:59 am
Do you have an incandescent test light?
Title: Re: Having problems with hazard or brake lights always staying on
Post by: Frankgomez1965 on May 10, 2017, 03:20:48 pm
Is that like a regular 12v test light? Yes I have a 12v test light
Title: Re: Having problems with hazard or brake lights always staying on
Post by: bd on May 10, 2017, 04:14:28 pm
An incandescent test light uses a filament type bulb as opposed to LED.

When you unplug the turn signal switch, probe each of the female terminals in the dash harness connector using your test light.  With the ignition switched OFF, only the black and brown wires should test hot; with the ignition ON, the purple wire should test hot, as well (don't be alarmed if probing the brown and purple wires energize the respective flashers).  The white wire should become hot only when the brake pedal is depressed.  If the remaining wires are dead, replace the turn signal switch.  Let us know the results.
Title: Re: Having problems with hazard or brake lights always staying on
Post by: Frankgomez1965 on May 10, 2017, 04:35:08 pm
Is the dash harness the one that plugs into the back of the dash cluster?
Title: Re: Having problems with hazard or brake lights always staying on
Post by: bd on May 10, 2017, 06:45:05 pm
The dash wiring harness is the collective electrical wiring behind the dash that is taped together into a bundle with branches that run to the various driver controls and electrical appliances to supply power and ground.  The instrument panel (or dash cluster) wiring is part of the dash harness, as are the factory radio wiring, the HVAC wiring, the turn signal switch, headlamp switch and ignition switch wiring, the courtesy lamp wiring, etc.  Each appliance and/or switch has its own dedicated connector that plugs into a mating connector, which is part of the taped wiring harness. 

The dash harness electrical connector for the turn signal switch is typically a flat, black plastic plug about 6" wide x 1" deep x 1/4" thick that attaches to the side of the steering column behind the dash.
Title: Re: Having problems with hazard or brake lights always staying on
Post by: Frankgomez1965 on May 10, 2017, 08:42:51 pm
Oh ok. Thanks for helping me out. I'll check it when I get a chance.
Title: Re: Having problems with hazard or brake lights always staying on
Post by: Frankgomez1965 on May 11, 2017, 06:25:58 pm
K finally got around to testing it with test light. White is only wire that is hot, stays hot with ignition on or off.
Title: Re: Having problems with hazard or brake lights always staying on
Post by: bd on May 11, 2017, 07:30:19 pm
Unplug the brake light switch and recheck the white wire.
Title: Re: Having problems with hazard or brake lights always staying on
Post by: Frankgomez1965 on May 11, 2017, 09:37:35 pm
I think I figured the problem out. White brake switch wire was shorted/melted together with orange hazard light wire behind fuse box.
Title: Re: Having problems with hazard or brake lights always staying on
Post by: Frankgomez1965 on May 11, 2017, 10:26:55 pm
👍
Title: Re: Having problems with hazard or brake lights always staying on
Post by: bd on May 12, 2017, 12:54:40 am
Well, there you go.   8)