2003 chevy 1500HD lighting issue

hi, i have a friend with a 2003 chevy 1500HD quadra-steer LT. the two rear brake lights are not working. the brake light on the cab is functional, and i also get 12v on the trailer brake plug, just nothing on the bed mounted brake lights (bulbs are good, just no power at the sockets). i replaced the

4 plug wiring block mounted on the rear cross-member and it made no difference. i have power going through all my fuses also. before searching for an odd issue somewhere, im hoping someone can suggest any common or known issues. thanks,
Reply to
Nathan W. Collier
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hey Nate, wazzup? Most commonly, when I was at the dealership this was caused by a fuse in the fusebox up under the hood. Most people check the fuses in the dash and not up front.

-- Old Crow "Yol Bolsun!" '82 FLTC-P "Miss Pearl" '95 YJ Rio Grande BS#133, SENS, TOMKAT, MAMBM

Reply to
Old Crow

howdy wallis, been a _long_ time! i hope all is well with you and yours.

i found only one fuse in the front box listed as stop, and it appears to be good. were it bad, wouldnt all the brake lights fail? im not familiar with the schematics on this particular truck since its not mine. im just trying to help out a friend. will probably start searching for a schematic online.

thanks, good to see you around.

Reply to
Nathan W. Collier

Montana

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Nate, just curious have you run a multimeter over the fuses or just going by looks. I know when I was doing the Car Audio gig, I had many

100's of time where it would "look" good but was not.
Reply to
azwiley1

absolutely. checked both sides of the fuse for 12v. is there more than one stop light fuse under the hood?

Reply to
Nathan W. Collier

the left and right brake lights are wired though the turnsignal switch which is a common failure in fords ( multi- function switch ) dodges have been known to also have this problem

Reply to
samstone

I don't have access to the GM tech site anymore(since I quit the dealer and went to work on old cars)but as I remember the 3rd brake light is independant of the other two. I also don't remember if the '03 has the separate brake and turn lights. If not, you might check the t/s switch.

-- Old Crow "Yol Bolsun!" '82 FLTC-P "Miss Pearl" '95 YJ Rio Grande BS#133, SENS, TOMKAT, MAMBM

Reply to
Old Crow

Does the running/parking lights on bed work?

----------------- TheSnoMan.com

Reply to
SnoMan

wow.......i never considered that. thanks.

Reply to
Nathan W. Collier

yes, running/park lights work fine. just no brake lights on the bed.

Reply to
Nathan W. Collier

According to schematic, all lights share a common ground. On the power feed to rear of truck are rear distribution bolck there is a single LT Blue wire going into C1 pin "B" that feed boths stop lights via pin "D" in C2(LR) and pin "A" in C4(RR).- Cx means connector number. Check for power going into C1 pin B on LT blue wire.

----------------- TheSnoMan.com

Reply to
SnoMan

found the problem. when the lights went out the original owner had tried new bulbs but didnt get the right bulbs. when i looked at the truck and replaced the frame mounted wiring block the lights still didnt light up, but i didnt recheck the sockets at that time to see if there was power on them. it was a combined issue of the wrong bulbs as well as the blown wiring block. thanks all,

Reply to
Nathan W. Collier

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