Problems rewiring trailer

[NW_Subie]

I'm having a problem rewiring my trailer.

When I turn the cars running lights on, the running light vehicle fuse blows. I've ground each light to the trailer frame. I tested each light before hooking it up and the light worked.

Hoping the wiring gurus have some sage advice. Do I have a bad ground or a short in the rear lights. Do I need to ground the trailer in a different way?

I've wired it for four flat.


The main ground is here on the frame.


The front running lights are spliced here to the brown wire on each side.


The front running lights are each ground to the frame.


The rear lights are here. Red is for running light and black for turn/brake.


Again, rear lights ground to the frame.


Any suggestions would be most appreciated.

[madjack]

...blowing fuses is usually a problem with a short circuit...that would be the place to start your search.......

[starleen2]

Possible live wire shorting to ground. Check all wires for bare copper or places where a wire or cable could be pinched. By any chance do you have a pinched wire somewhere? I had that happen on a NEW trailer. A pinched wire that grounded and kept blowing fuses. The wiring worked just fine unitl I tighened the floor down to frame - and bingo - instant power to ground short! Check everything - don't assume - my ground problem was in a spot that I couln't even see. Almost drove me nuts until I did an continuity test on the strand and knew for sure.

[bobhenry]

It appears all of your ground connections are accessable. If this is true unhook all of the grounds to each individual light while leaving your main ground connected. It avoid damage to your tow vehicle use a battery charger to power the brown lug on the 4 way flat. ( Hot to brown and ground to frame). Touch each ground wire to it's ground if the light functions it is not the problem child. Continue until each light is tested you will find one will not function and the ground should spark excessively when connected. This is the culprit!
You will most likely find a screw ran thru the hot wire or as has been said a wire pinched thru the insulation.

[Forrest747]

Ok i noticed you spliced into several of the wires, normally not a big deal, but sometimes the clip that covers the press down, does not stay down. making contact with frame and pow. Just a thought.

[NW_Subie]

Thanks for suggestions. When I was testing the right rear light the ground really sparked on the frame and the the car fuse blew. I'll take the light apart and see if I can find the problem. I think the short existed before I rewired. The lights weren't working properly. The 2nd owner had replaced the original rear lights.

Round lights.


Original lights.

[bobhenry]

If it is the lamp holder itsself , you can buy just the lamp holders alone in dozens of configurations at any good automotive parts house if you want to keep the actual light fixture.

[NW_Subie]

Does a short in the wiring of this lamp make sense?

[bobhenry]

Hook it up and ground the housing, It looks good but it is very possible.

There is a spring in the bottom that lifts the bakelite waffer that holds 2 buttons that contact the tail and turn contacts on the bulb. If their crimped tails contact the spring Pow! Do they look bent, does the socket looks as if it has been overheated.

Wouldn't that be a kick in the ass, a 3 dollar socket causes 2-3 days of aggrivation.

I wired a couple clearance lights using some old 2 wire extention cord. I melted a feed wire and chased gremlins for a week only to find that the cord I used ,while looking good on the outside the sheath on the individual wires had deteriorated internally and the insulation jackets inside had turned brittle and cracked allowing my hard wired ground to contact the hot wire. Who would have thunked it , strange things occure

[Forrest747]

anything is possible with that socket. i would replace it, it cant be all that much. and see if that fixes your problem.

[bobhenry]

WELL ? What was the problem ?

we need to know

[NW_Subie]

Haven't had time to work on the trailer.

Had to focus on taxes.

[NW_Subie]

To avoid damage to your tow vehicle use a battery charger to power the brown lug on the 4 way flat. ( Hot to brown and ground to frame). Touch each ground wire to it's ground if the light functions it is not the problem child. Continue until each light is tested you will find one will not function and the ground should spark excessively when connected. This is the culprit!

What type of battery charger should I hook up to the 4 flat? I've got a trickle charger that plugs to a GFI 110 outlet. Would that work? I too would prefer not to damage the tow vehicle. Besides, the auto fuses get expensive.

[Forrest747]

This is what I did for short on a friend landscaping trailer. She had a 4-pin. The first thing i did was to ohm out the plug. they should all show as open. the left one was bad and showed as a short. and traced it back to the socket. socket looked good, but just replaced it. ohmed out the plug again and all open (a good thing) pluged the bulb in and things went on thier way.

[bobhenry]

Haven't had time to work on the trailer.

Had to focus on taxes.

Well it's the 16th hope your taxes are done.

Now on to more important things. If you have a 6 to 10 amp battery charger use it they are generally better protected and if it has the ampere meter on it you can "see" a short as it will draw way to many amps.