twichit

Evening to all the masters of wiring. First the problem, about a month ago on a road trip in the middle of nowhere I started smelling what i thought was hot wires[this was at night with all my lights on]. Shortly after that {2 weeks or so] my headlights stopped working, I had running lights but no high or low beams. This afternoon I did Jim Lanes relay wiring harness for the headlights [minus the hi low beam relay]. Still no headlights I started pulling the headlight switch out to replace it and once i got it low enough to start disconnecting the plug and switch like magic the headlights work,hi and low just the way its supposed too. now with that being said I have not put the new switch in but I am wondering if i should start chasing harness, I would rather not but I don't need my truck burning up as it is my only set of wheels,thoughts?

Philip

Did you check the light switch harness plug. They are noted for melting. When that happens you have loose connections and all sorts of issues.

If yours is a dually and you tow a trailer the problem is more acute.

GasganoFJ60

While I'm not a wiring expert I can say I'm in a similar boat as you.
My headlights needed to be replaced(they were a few years old and had condensation in them) so I did just that. A few days later my lights had the same symptoms you describe; running lights, no headlights. Headlight would only come on if I pulled back on the high/low beam switch on the column.
Figured it was my headlight switch, again, so I picked up another one.
Upon pulling off the old switch I saw, inside the wire harness plug, a nice'n'crispy burn spot in the middle of the harness.

While trouble shooting with the problems in my wiring gremlins post I pulled the switch, scraped out some of the crispy plastic and managed to get the lights to work again as they should.

But I know a major overhaul of the wiring is in my near future.
While I'm sure my post isn't very helpful, I hope it helps you feel not so alone and can help mentally prepare you for what may be coming your way as far as truck projects go.

I can feel this be a growing issue with fellow 1st Gen owners as Father Time continues to beat these old Chryslers with his ugly stick.

twichit

Mine is just a single rear for now,but it has towed goose neck when i need it too, and the three p.o used it for a tow rig.. I know the last owner hauled cars with it all over new england and beyond i also have already fixed the trailer harness and brake controller wiring gasgano ill check the plug and switch for giggles my other 93 did end up burning that harness out before i got it,then it did it again when i had it

Philip

Dodge does not have that head light plug anymore. They do have one for 94+ model trucks. It is the same plug with some different wire colors. Just wire it in by position of the wire.

Between my truck and friends I have replaced around 6 over the last decade.

Last kit I bought was $67 out the door. That included a new head light switch.

NAPA switches only lasted for about 1 year. Factory switches last longer for about the same price.

Put that center terminal on a relay. That is the tail/trailer lights. A dually and trailer eats the terminal block and switches. There is a sticky thread on doing the tail light relay mod I think.

twichit

Philip thats next on my wiring to do list i believe j martin did a write up on that issue gasgano just checked the switch and it is covered in dust it dose look like a pin got hot but it hasnt destroyed the switch so im going to clean it and see what happens also the wiring looked fine

j_martin

When a pin gets hot, the internal crimped connection in the switch is compromised. It won't get better just because you clean the scale off the connector. In other words, if it does work, it won't work for long.

The headlight switch and connector are a well known weak link in the electrical system.

Replace the switch and the connector. After market parts will work. Also put in head light and tail light relays.

Jim's headlamp relay setup is a good one. I did that with Custom Connector BR-05WP relay sockets and weatherproof relays.

The tail light and clearance light circuit has an in harness splice close to the headlight switch, so the most reasonable location for a relay is under the dash near the headlight switch. You don't need a weatherproof relay there.

That's a permanent repair. Anything less is a patch.

twichit

j martin the old switch ended up going bad last night while i working on it the new was switch was put in and it is all good, i have not done the tail light relay yet as my current pay scale will only go so far,but i will start planning to do that next. If i ever sell this truck or someone else has to work on it they will be cursing me, i wired it like a locomotive,all one color the plan for today is fusable links goodie

james1

I agree that Jim Lane's instructions for building a headlamp relay circuit are easy to follow, but I confess to taking the lazy way out and installing a headlamp relay circuit from Painless Performance and simply putting LED bulbs in the clearance lights and tail lamps.

(Electrical work is not my strong suit. I was about to throw a PCM at my last electrical issue, which would not have cured the malady, Fortunately John Martin solved my problem and saved me beaucoups $$.)

The Painless product took about 15 minutes to install and was not so expensive a few years back when I purchased it: Painless Performance Headlight Conversion Harnesses - 30815 - Free Shipping on Orders Over $99 at Summit Racing

Can someone please confirm that the Mopar part number for our headlamp switch is: 4565 320?

TIA.

N. Besonderes

Even with the lights on relays, the switch will get smoking hot if you don't leave your dash lights at the brightest setting.

Niemand

j_martin

I don't think this is a problem with stock dash lights. If you add a lot of extra instrument lights and don't change over to leds, you can overheat the series variable resistor (dimmer).

Solution, either convert all to leds, or use an emitter follower amplifier (a transistor on a heat sink, and a couple of small resistors) to control the added lights.

N. Besonderes

Well, I'm sure you're right but, perform this test:
Turn on your Park Lamps, with your dimmer turned all the way up (just before it clicks over to Dome Lamp), and leave it on for a few minutes. Then, reach up under the dash, with your left hand, and feel the Head Lamp Switch Housing.
Next, turn the Dimmer **** down just a little bit and then, after another few minutes, reach up there and feel her.
For me, even after installing relays on Head Lamps and Park Lamps, the resistance in the factory switch's rheostat is was still enough to make it blistering hot with just the slightest deviation.

Niemand

j_martin

Of course, that's how a rheostat works. It converts electrical energy to heat.

That part of the headlight switch is supposed to get hot. It is designed to control a specific load, that is the dash lights originally installed in the truck, plus one or two extras, like in a factory tachometer. Overloaded, it will overheat.

LED's will reduce the load, which will reduce the heat, but also make the adjustment range different, as in it won't dim all the way down.

There are electronic circuits that can use the voltage from the dash lamp circuit, but very little current to control more lamps from a second power source. An emitter follower circuit runs hot but electrically quiet. A PWM circuit runs cool, but can emit radio noise.

N. Besonderes

Interesting.

james1

For posterity, the OEM headlamp switch part number (Mopar) has changed. It is now: 5602 1898AB. Unfortunately, the list price is more than $60.