Brake lights

[95nismohardbody]

heres the problem... i am havin trouble out of my brake lights.. as long as the headlights are not on they work fine except the running lights come on when i hit the brakes. but my real problem is when i turn the headlights on the brake lights come on like i have my foot on my brakes. i have changed my brake light switch... my head light switch..all the bulbs but nothin changes... i have heard it might be the grounds but i dont know where to look for this... please help

[PhillyHardbody]

You have crossed power wires somewhere, probably somewhere close to your steering column. With wiring diagrams for the headlight and brake light circuits I could probably tell you where to start looking.

[longtooth]

I would check your fuses for a blown one. I have seen them do weird things. Also do you have a wiring harness for a trailer on your truck?

[95nismohardbody]

i havnt touched any of the wires near the steerin column..i have put in an aftermarket dvd player..the old stereo was stolen an the original wiring harness was torn to peices when they done this...i taped all the loose wires i could find an i ran the dvd straight to the fusebox... im not sure if the brakelight were working before this because the trucked was parked for over a year... i dont know where to find diagrams it is a 1995 hardbody if you can help... an to longtooth ive checked the fuses an none are blown.. an it doesnt have wiring harness for a trailer.. thanks for the help guys

[PhillyHardbody]

True I forgot about the redundant wires they sometimes ran on these older vehicles, I would suggest checking the fuses as well, especially since you say you wired your dvd player straight into the fuse box, maybe some wires got crossed when you did that somehow. With the symptom your giving you're getting power on circuits where you shouldn't be have power so the only option is that you have crossed power wires or the truck has multiple circuits to power the brake lights in case of a failure elsewhere which means if you fix the problem in the main wiring things should go back to normal.

[RT22]

Remove dvd player and see what happens if nothing that is not it but if it fixes lights then you know it is in your dvd wiring that the mess up happened.

[Novajoe]

The running lights are coming on instead of your brake lights when your headlight switch isn't on because your brake lights aren't getting any power unless your headlight switch is on(both light up when I press my brakes).

do your turn signals still blink when your headlight switch is on?

when only turn your running lights on (headlights one click up) what happens with your tail lights?

[Q451990]

Sounds like a short between the two tips on one of the combination bulbs in the tail/brake lights. I would unplug each assembly one at a time to try to isolate it. I've had this happen on my Q45 and it uses the same bulb type.

Heath

[Novajoe]

Sounds like a short between the two tips on one of the combination bulbs in the tail/brake lights. I would unplug each assembly one at a time to try to isolate it. I've had this happen on my Q45 and it uses the same bulb type.

Heath

I could see this if it were only one light, but the likelyhood of it happening to both at the same time is pretty low, especially since these tail lights are wired in parallel(independed of one another).

[Q451990]

It only takes one to back feed from one circuit to the other through the bulb.

Heath

[Rockski]

i havnt touched any of the wires near the steerin column..i have put in an aftermarket dvd player..the old stereo was stolen an the original wiring harness was torn to peices when they done this...i taped all the loose wires i could find an i ran the dvd straight to the fusebox... im not sure if the brakelight were working before this because the trucked was parked for over a year...

that bold part is where you went wrong... time to take it apart and start over with a proper wiring diagram, your hanes/chilton manual should have it in it