Short in a new wiring harness

[Marty Athy]

First time posting on here. Maybe someone has had the same experience.
I bought a new wiring harness from one of the reputable suppliers & there is a short in the headlight circuit. It is one with two tail lights, two turn signal leads to the front bumper, & the turn signal switch. No problems running without headlights on or with parking lights on. Only has right rear blinker, & both lights have power on that side when head or parking lights are switched on. Disconnected all the lights & it still blows the fuse when you turn the light switch on. The light switch is quite hard to operate as well.
Thanks in advance if anyone has any idea's.
Marty

[J Franklin]

Welcome to the forum. Return it for a good one.

[C26Pinelake]

Did you contact the vendor ? Wayne

[Dick Steinkamp]

Disconnect the headlight harness at the headlights (both sides). If it still blows the fuse, the fault is likely the harness. If not, the fault is likely internal to the headlights.

[larrys40]

Marty,
I agree with Don that the harness is probably ok. The problems like you describe are usually within the sockets and connections. Sometimes wit the repro and even original socked when the back part if the socket gets loose and wires may have issues where they go I the spring contacts they can short there as well as have issues at the stick connectors at the headlight conduits . Disconnect one at a time and that may help narrow it down . Weather it blows of high or low beam will also give you a clue .

Narrow it down and let us know . Should be easily traceable and fixable.
Larry Shepard

[Ed Saniewski]

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Marty, you said you disconnected all the lights. Are the wire ends then hanging out in the free air and it still blows the fuse? This would take the head and tail light buckets out of the theory.You could then take an Ohm meter and check each end to ground and find the problem.

[C26Pinelake]

A short in new harness is highly unlikely. Look as the others have said to Your lights themselves. Wayne

[Ray Young]

When my lights developed a dead short I eventually took the headlight switch apart and found a small blob of grease inside that would make contact when the switch was turned. Probably not a common thing but worth a look.

[larrys40]

Marty
I reread your thread again ...
Not sure what kind if ten signal switch you are running, signal stat or brain Box type, but you may have a wiring problem from the switch. Also if the switch is hard to move it could be a ligt switch issue or maybe your inside harness head isn't seated properly. Also, check for proper grounds as required. If you know how to use a volt/ohm meter you are just going to have to trace it down. If you feel the harness is truly the problem then call the vendor to discuss. If there is an issue with the harness it really has to be at the light head
I believe they sent a schematic with it so check the wiring and codes for correctness

This is just one of those that tests one's electrical virtues and is a learning experience, no matter what the outcome .
Larry

[msmaron]

Here are some shots of REPOP vs. original headlight sockets. you can clearly see the difference when you look inside how they touch each other and it would always cause a short and the bulb to blow, Also note how the wires are attached outside...

[Y-Blockhead]

Originally Posted by msmaron

Here are some shots of REPOP vs. original headlight sockets. you can clearly see the difference when you look inside how they touch each other and it would always cause a short and the bulb to blow, Also note how the wires are attached outside...

I have never understood why there is not a fiber 'separator' above the springs to separate the wires like on more modern light sockets. I retrofitted mine...

[Brentwood Bob]

Check the soldered ends of the wiring at the plate.
There is a chance one of the ears is out of position.
The repo harness plates don't fit very well in the repo light switch housing.
Since you said the switch is hard to turn I am suspicious of the plate.

[msmaron]

Originally Posted by Y-Blockhead

I have never understood why there is not a fiber 'separator' above the springs to separate the wires like on more modern light sockets. I retrofitted mine...

HAHAHAH The reason there is not.....get ready for it....."IT'S A REPOP!!!!"

[Y-Blockhead]

HAHAHAH, how come I don't see it in the original either? I said above the springs...

[msmaron]

No reason for it in the originals...no need and it would have cost ford MORE MONEY that he deemed and his engineers did not need....which is true you don't.,

[Jeff/Illinois]

Originally Posted by msmaron

Here are some shots of REPOP vs. original headlight sockets. you can clearly see the difference when you look inside how they touch each other and it would always cause a short and the bulb to blow, Also note how the wires are attached outside...

Now here is a part that begs accuracy. The repops are pretty bad. This and the headlight switch. Someday someone will step up to the plate and make these parts GOOD parts. My guess would be Bratton's or A&L. Must be pretty expensive to do it right

[Chuck Sea/Tac]

Originally Posted by Ray Young

When my lights developed a dead short I eventually took the headlight switch apart and found a small blob of grease inside that would make contact when the switch was turned. Probably not a common thing but worth a look.

Did someone put conductive grease on the socket connections? Usually grease is non conductive.

[2manycars]

Originally Posted by Jeff/Illinois

Now here is a part that begs accuracy. The repops are pretty bad. This and the headlight switch. Someday someone will step up to the plate and make these parts GOOD parts. My guess would be Bratton's or A&L. Must be pretty expensive to do it right

Several years ago when Al Lepore was still allive, I asked him about reproducing the light sockets. He said it would cost $10,000 at that time to make the dies and produce the sockets. He also said that the repro (some call it repop) sockets were better than earlier, and he felt the investment would not pay off. I suspect there are more than one manufactuer of the sockets, as I have used some good quality repro sockets with good results. Maybe it does matter where you buy, and what you pay. But some people only shop by price.

[Mike V. Florida]

Originally Posted by Y-Blockhead

I have never understood why there is not a fiber 'separator' above the springs to separate the wires like on more modern light sockets. I retrofitted mine...

Here is where to get them, Pigtails

[Marty Athy]

Lots of good stuff here guys. I appreciate it. I do have all of the lights disconnected & ends are clear of a ground. I will take the switch loose & take the ohm meter to it. Makes sense there could be something grounded in there from the manufacturing process.