ok so last night i was driving around with a cupple frends. I backed up out of a parking spot and wen we got back to there place he told me i had no back up lights. I dident think much of it so today i checked the fuse shure enuf blowen so i changet it put the truck in reviece and still no B/U lights. I went and checked the fuse and it was browen again. Now under my truck there is a bad spot in the wirring i found a while back wen i had no rear park lights. Somone before me scotched locked trailer wireing between the cab and box then took it out and dident tape it so there is the cut in the sheatiing. Anywaus i went under there we i had my park light prob and fixed it, i soderid then together and put shrink tubing over it. Anyways that was the first place i checked the fix was still good. So i went up by the front fender down my the frame where the plug for the harnes is unpluged it, put in anouther new fuse (my multymeeter is at work) and still poped it. so where do i look from here i was hopeing it was something simple but its not lookin so? any ideas anyone? anyone had the same prob? Im pritty good at this eletrical stuff but just wanting imput before I go any futher

 

I had an almost identical problem, previous owner did a shiat job of installing the trailer harness and the wires corroded. Check all the wires and maybe replace the bulbs. The switch is located right in the transmission (for Reverse) so you could take the multimeter when you get it back from work and start there, working your way back to the bulbs. My trucks reverse lights won't go on sometimes, and I have to just wiggle the shifter (gently tapping upwards) and the lights come on.

 

yah the bulbs are good i checked them (put in new ones) and i know its not along the frame cuz i unhooked it from the plug at the front of the frame by the fender yah i juess ill half to start at the tranny and work forward [:'(] not looking forward just wondering if anyone had them short out at a certan spot or something for me to start at

 

i have the same problem, the reverse lights will not work until i unplug the wiring harness. the harness is brand new and hooked up correctly, but the lights still do not work.

 

well then that would tell my you have a short along the frame somewhere or in the taillight/BU harness somewhere

 

best way to start is to shoot for a short to ground first.. obviously something is grounded for the fuze to blow that quick... there should be continuity(sp) between the live wire that carries power to the R lights and to ground. if theres no continuity to ground then its gonna be shorted on something else.. a signal wire that carries a different voltage or an isolated ground of some sort... it would matter if it was another 12V source wire b/c your R lights would be on all the time or interminantly

 

yah i dident have my multymeeter here this weekend so i couldent do a good check so i prob wont get to testing it till next weekend now B/U lights are an option anyways right lol the tryck moving backwards is a dead giveaway. have you ever used one of those testers that is susposto tell you what direction the short is in? i dont even know how much they are but if they work i might look into one...i hate chacing shorts im the kinda guy that tends to just run a new wire rather than find the short but in thise cace i wanna fix it. i think it would be more of a pain to rewire it from the tranny up. i guess ill have a look at the merry xmas mannuel and see in i can find a wireing diagram...sounds like noone else has really had a prob like this so ill just dive in...next weekend

 

i know what meter your talking about..shows you where the break is and how far in the wire the break is at? they are so nice.. i used them all the time in the military working on crappy wiring on the jets... its called a Time Domain Reflectometer, or aka Digital Metallic Time Domain Reflectometer ... and thats no joke either.. thats the real name ,, no startrek uss enterprise warp core part either lol... what it does is send electrical pulses down the lead or wire and when the pulse hits the break or ubstruction (10ga into 2ga back to 10ga, for whatever purpose or reason) it reverses and acts like sonar and gives the meter a general idea where the break is..VERY usefull when your dealing with hundreds and hundres of hidden 22ga wireing in modern day fighter aircraft and weapons (me)

for a decent one...youd spend around 50,000 bux .. for a crappy one.. looking close to 10,000 bones.. and i know know 2 compnays that make and sell them... goodluck!!!

i agreee... either run a new wire or just shoot for the break.. you never know..finding the break wherever it is could give you an idea if theres other wires about to do the same thing .. say chaffing or burning from an exhaust or other sharp object

 

HOLEY SHIET 50 000$ i think ive seen them before but i know no shop would have one for that price in guessing thats in USD too!!! duz this thing come with something that not only finds the break but fixes it for you gets you a beer then washes the truck as well it better for that price! anyways duz this thinf look almost like a pen but a bit bigger around i cant rember if it probed the wire or clamped around it but it i think 5 leds on it and it lighted up whatever side the short was on and the closer you were the more lights came on. have you ever herd of something like this i could sware ive seen them before but like i sed no shop or mechanis could spend 50 000 or even 10 000 on a tester

yah thats part of the reason i wanna find it rather than just running a new wire is to make shure there is no outher probs there.

if its poping the fuse the short has gotta be after the fuse obvusally right now do you know if the wirring goes power into the tranny switch the out wen you put in in R to the fuse then from the fuse to the R lights now i know is not along the frame rail so it would half to be between the fuse panel in the cab ant the plug on the frame... thats not a verry bug chunk of wire... that is if in understanding this right... i cant find a good wireing diagram thow

 

oh LOL yea i know what your talkin about.. i thought you meant a TDR,,, them things wont get you a beer but are worth there weight in gold... its got a tv screen on it.. kinda like a scope on riods... with about 100 different connectors for it..comes in a breifcase.. the price is just what i remember from the military.. the military always spends an extra 40 to 90% on the crap they buy just cuz they can..

i know that pen thing your talkin about.. like 6 inches long and 3 LED's on each side and has probe lookin things on either end ,, some have wires coming out as test leads... ive seen them before..jsut cant remember what their called... ill try to think...used to have one in the install shop..no one every used it..

the break could possible be before the fuze and if its shorted to ground it could very well still pop the fuze b.c its still drawing .. youd just suffer from a dead batter if its before the fuze and since you havnt mentiond that problem id be on the aft side of the fuze theroy.. im not sure the exact circuitry of the R and rear lights system.. knowing the automakers now a days its prolly all relayed so it just sends the switched R power to the rear instead of an actual circuit stringed along the length of the truck... and grounded at the rear also... but im not 100% positive... thats the downside to most automotive wireing diargrams... they show HOW the circuit/s are ran.. but not WHERE the circuits are ran..