im stumped

lukecline

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Ok ive got a weird problem.... On my 97 i keep blowing fuses to the trailer lights, it doesnt matter if the trailer is hooked up or not. Its been doing this for awhile, but i was unaware how often til our driver told me about a week ago. Anyway i take a look at it today, put a 25 amp fuse in (#4 fuse under hood) and we have lights (old fuse was blown very bad, big gap between posts). I pull fuse and put my fluke meter between fuse terminals and its drawing about 1 amp, now im thinkin how in the heck are we blowing a 25 amp fuse that bad! I set my meter to record peak amps and crawled under the truck and wiggled all the harnesses going all the way to the trailer plug....max amp draw 1.0. So i put my meter up start backing out of the shop and pop there it went. I put truck in park, pull fuse and its blown bad. Now im out of 25 amp so i throw a 20 in, start backing out POP . I am not going to hook my meter upto that unless i can rig up something i can use my amp clamp with. Anyway i put it in N put new fuse in and then drive around parking lot...lights still on, put in reverse and POP goes the fuse WTF?????

Oh i bought this truck with a salvage title, it was the victim of a small eng compartment fire on the passenger side. Ive had absolutely no problems in teh 10k-15k miles ive owned it other than this. Any ideas? Im an electrician by trade so im familiar with wiring, but i dunno where to start with this

luke
 
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Crumm

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In the trailer wiring harness there is a circuit for back-up lights. It sounds to me like there might be a short in the harness causing the taillights to short out when the reverse lamps come on. I would start at the trailer plug and make sure someone did not hook up the reverse lamp wire to something it should not be hooked too(like ground).

edit: you might also find the reverse wire if it is not hooked up to ground, it might just be laying back there touching the bumper or something. I forget what color it is but if you can't find it I will go look under my truck and see. I use mine to bypass my trailer surge brakes when backing up.
 

rickh

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Hi Luke, sorry I missed your call today.
I would bet it is in the connector on the back of the truck, where ever that is, in the bed on the bumper wherre ever. The MALE TRUCK SIDE. I will bet thats wherre the problem is, probably all corroded up.
Rick H...
 

95psdF250

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Just don't back up anymore and you will not have the problem....:D

It does sound to me like the backup wire is some how connected to the trailer ground wire on your trailer plug on the truck side.

This would mean that when the trailer is not connected you will not have any problems but as soon as the trailer is connected and grounding through the trailer tounge and truck ball then you will have a dead short for sure.

I have actually had this happen on one of our trucks when I was living in NY.
We bought a used PSD and when we hooked it to the trailer and tried to back up the fuse would pop everytime. Took me a little while to track it down but that is what I found to be the whole issue.

Good Luck with it.

Later,
Darrell
 

lukecline

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ok went out and did some more checkin, this truck has the trailer package or what ever ya call it so it has separate fuses for the trailer lights. I pulled the trailer plug out on the truck and checked the wires there to roreri's list and they didnt match up :whah. Right now i have a solid orange wire that has power all the time and a black w/ green tracer seems to be the backup lights. Oh and once i pulled the plug out of bumper the fuse doesnt blow anymore. The trailer plug is wired using a pigtail that plugs into two different plugs on the truck.

luke
 

powerboatr

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lukecline said:
ok went out and did some more checkin, this truck has the trailer package or what ever ya call it so it has separate fuses for the trailer lights. I pulled the trailer plug out on the truck and checked the wires there to roreri's list and they didnt match up :whah. Right now i have a solid orange wire that has power all the time and a black w/ green tracer seems to be the backup lights. Oh and once i pulled the plug out of bumper the fuse doesnt blow anymore. The trailer plug is wired using a pigtail that plugs into two different plugs on the truck.

luke
"The trailer plug is wired using a pigtail that plugs into two different plugs on the truck." yes thats correct it should be plugged in not spliced.
if its spliced... well you know the answer.

the orange is supposed to be HOT only when the engine is running.
although i have found some had POWER when the key was on.
its the 12 v trailer battery charge feed.

sounds like your bumper plug is screwed up.
 
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powerboatr said:
sounds like your bumper plug is screwed up.

Sorry for the hijack, but that quote coming from Robert just cracked me up!!!:roflmao :roflmao

Luke,

I hope you get it fixed fast, just so Robert doesn't have to talk about your "bumper plug" anymore!!!:sorry :lmao :lmao
 

lukecline

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lol thanks for the help, put new plug (this one isnt corroded at all) and some how it fixed the problem!

thanks,luke
 

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