VCCA Home Forums GENERAL DISCUSSION General Discussions Melted electrical connection...what to do?

So I put a headlight wiring kit from LMC Truck on my '96 Cherokee that circumvents the normal wiring and runs the headlights directly off the battery by way of a relay. The kit runs the lights at 55/100 (low, hi) watts instead of the original 55/60. One reason I did this was because the light output was terrible, and the other was because for some unknown reason the headlights would shut off after being on hi for a bit. Never did this on low. I've had the new wiring kit on for a few years now and it seems to have solved the issue.

The problem I'm having now though is that this new harness is melting at one of the connections...



You can see only one of the wires is overheating while the other seems to be ok. I'm guessing the hot one is used by the high beams.

What could be causing this? Could it be related to why the high beams used to shut off before I replaced the wiring harness? A while back I asked about the shutting off issue on a number of Jeep boards but nobody had heard of this particular problem before.

Looks like the connection is loose, dirty or just cheaply made so it is overheating the contacts of the connector and then melting the plastic.

It looks very close to failure. You will need to cut off this connector and either connect/solder the wires together or find a quality connector at a store like NAPA and install it after removing the melted connector.

Check the connections on the other end of this wire as well and maybe check with LMC on warranty or known issues.

Your picture of a portion of your wiring bothers me. #1, I don't like splices in wiring. Should be a continuous wire. Something to always consider is wire connectors. They must be tight and make full contact. Bad connections cause heat that could melt the connection and cause problems. All connections should be disconnected occasionally and reconnected. Cleaning with electrical cleaner is also a plus.
Looks like you need a new cable or end for the positive cable also.

When the lights were shutting off, you were probably tripping a circuit breaker because of the oversize bulbs. This is a problem that usually shows up on much older cars, due to an increase in wattage of "standard" sealed beams.

The relay kit just looks too small to me. If you are correct that the melted one is feeding the high beams, then at 100 wats per side, 200 Watts / 14 volts = 14.3 amps through that little spade lug. It might technically be ok when everything is new, i'm not sure, I would never do it. I would expect it to melt.

I can't tell for sure what size that wire is, but it sure looks too small. As Antique Mechanic pointed out, splices are bad. Every connection has a little resistance. Every little bit of resistance causes heat and voltage drop. Bulbs are very sensitive to voltage, Any loss matters if your goal is bright headlights.

I can't imagine why that connector is even there.

If it were me, I would probably redo the whole thing. Daniel Stern has connectors and so on to make up the wiring using locally sourced wire.

https://www.danielsternlighting.com/

Failing that, to just repair the melted stuff, I would eliminate that connector. Run some nice heavy wires from 12V all the way to the relays. I would probably use #12, though I think #14 would be ok.

The back of the alternator (or somewhere closer than the battery) is normally a far better source for headlight power, but on a rig as new as yours it probably wont make much if any difference. When you connect your headlight power wires to the battery, the headlight current is pulled through the charging circuit whenever the car is running.

On older cars the charging circuit wiring tends to be small, and may overheat. Also, on cars with an ammeter the headlight current registers as "charge" when it isn't.

I would stay on JEEP message boards to maybe find a good JEEP mechanic
too many band-aids have been holding this together for too long.
my 2 cents

Heat is the product of a bad/poor connection, or a loose connection on a high constant amperage draw circuit will cause that type of failure at the connector. Electricity is electricity, it don't matter if it is Jeep, Chevy, or a Ford, ohms law is ohms law.
Good Luck