Brakelights stay on

[satmike]

01 2500 brake lights stay on. Replaced switch still on. They stay on when switch is unplugged.
Any ideas would be great
Thanks Mike

 

[p-Bar]

Pull up on brake pedal and see if they go off

 

[satmike]

They stay on

 

[p-Bar]

I would assume the switch is normally open. So unplug the switch and see what happens

 

[DavidC]

Try unplugging trailer connector or short in harness.

 

[DavidC]

I would assume the switch is normally open. So unplug the switch and see what happens

I believe he already tried that

 

[p-Bar]

Try unplugging trailer connector or short in harness.

Ya that's where I was going. Just wanted to make sure it's not a defective switch

 

[p-Bar]

OH yeah.

 

[satmike]

Stays on with switch unplugged. I plugged into trailer and everything works great. Unplug trailer and brake lights stay on on the truck

 

[satmike]

Unplugged the wiring harness under the truck for the trailer. A little green death in there, dialectic grease on the pins and everything works for now.
WE'll see

 

[DavidC]

Unplugged the wiring harness under the truck for the trailer. A little green death in there, dialectic grease on the pins and everything works for now.
WE'll see

I did the same about 10 years ago with the plug on the back of the trailer receptacle. It was turning on the brake and abs light at 40mph.

 

[3rdGenGuy]

Well I don’t know if your truck has a hybrid Integrated Power Module like my 2004.5, but I’ve tracked that issue to the big fuses on the firewall side, the big fuses, 30 to 50 amp. It’s fuses 11 & 13 on our 3rd gen trucks usually when that happens, the FCM power supply circuits. It usually happens when you have a corroded circuit board in the ICM/PCM(Power Control Module ....same thing). Honestly it’s a tear apart and repair of the board or a new Integrated Control Module from Dorman. Beyond that, the ECM on the driver’s side engine block will also have issues with the Primary Field Circuit for the charging system and also need to be repaired or replaced eventually. That’s what I know on my 3rd Gen.