Tech Talk Lights - Offroad/Headlights/Taillights and more

[FSHJNKY]

Are you looking to light up the trails? Thinking about a adding LED headlights to your rig. Whatever your need, want or desire this is the place to ask the questions and get the answers.
All light related questions will be moved to this thread for organization and simplifying the search functionality of the site.

[J&J]

The blinkers on the 01 TJ would sometimes blink a few times, then come on solid, or just come on solid, so I replaced the flasher. Worked great until I pushed the hazard button which made a buzzing sound (probably the flasher relay strobing) then went out. No hazards, no more directionals. I tried the original flasher which doesn't blink reliably, but at least the directionals would always come on. Nothing. Didn't blow a fuse either. So I figured the directional / hazard / lights multifunction switch was toast. Replaced it and tried both flashers. No blinkers or hazards. The lights still work fine. There's a voltage reading on most of the connector pins, though I don't know what I should be getting at this point. It seems like long odds that a faulty hazard switch fried the new flasher open and the original suddenly decided to stick open instead of closed right at that same time, but I'll be testing them next just in case. After that... Any suggestions are most welcome.

[FSHJNKY]

I know on my 2010 JK the LED’s need a resistor in line to cut the fast blinking not sure if that is the same for the TJ’s or not.

[Goat]

The blinkers on the 01 TJ would sometimes blink a few times, then come on solid, or just come on solid, so I replaced the flasher. Worked great until I pushed the hazard button which made a buzzing sound (probably the flasher relay strobing) then went out. No hazards, no more directionals. I tried the original flasher which doesn't blink reliably, but at least the directionals would always come on. Nothing. Didn't blow a fuse either. So I figured the directional / hazard / lights multifunction switch was toast. Replaced it and tried both flashers. No blinkers or hazards. The lights still work fine. There's a voltage reading on most of the connector pins, though I don't know what I should be getting at this point. It seems like long odds that a faulty hazard switch fried the new flasher open and the original suddenly decided to stick open instead of closed right at that same time, but I'll be testing them next just in case. After that... Any suggestions are most welcome.

Have you changed over the LED or are all your bulbs stock?

[Rubicon]

Not sure if I am reading this correctly, but if the lights work(light up), then it is probably not a fuse/switch/relay. Reads more like a flasher or fuse box issue(perhaps where the flasher goes), if they are simply not flashing.

I always use dielectric grease on the prongs of relays/flashers/fuses, as well as all connections. Plus occasionally/randomly spray the fuse box "female" cavities down with WD-40 to help lubricate, prevent corrosion, and dissipate any moisture(now and for the future ;)

[J&J]

Thanks guys. The lights are not LED, nor do we plan on changing them (yet - always a yet). I had my choice of flashers for incandescent, LED or both. I got the incandescent flasher because it came with a good warranty. The flasher plugs into the multifunction switch and both are new now so there's no corrosion (yet). I did test the new flasher as well as the new multifunction switch and they're working. I found a wiring diagram which doesn't tell me what voltages I should be expecting (though 10.77V should be right for most) but does help test for faulty wiring. The only anomaly I've found so far is one really poor ground on the switch connector. Since all the lights work and it ultimately ties into the light ground, seems I'll be chasing a bad wire from the switch harness side next, and probably won't have to chase it too far. Hopefully that's it.

[FSHJNKY]

Thanks guys. The lights are not LED, nor do we plan on changing them (yet - always a yet). I had my choice of flashers for incandescent, LED or both. I got the incandescent flasher because it came with a good warranty. The flasher plugs into the multifunction switch and both are new now so there's no corrosion (yet). I did test the new flasher as well as the new multifunction switch and they're working. I found a wiring diagram which doesn't tell me what voltages I should be expecting (though 10.77V should be right for most) but does help test for faulty wiring. The only anomaly I've found so far is one really poor ground on the switch connector. Since all the lights work and it ultimately ties into the light ground, seems I'll be chasing a bad wire from the switch harness side next, and probably won't have to chase it too far. Hopefully that's it.

I just read over the first post and realized that you said nothing about LED’s yet, I replied as if you did. Good luck.

[Goat]

An incandescent flasher is a current driven device basically what happens is the current flowing through the flasher relay heats up a bimetallic filament that bends into a banana from the heat breaking the circuit to the light bulbs...when the filament cools it straightens out and closes the contact again. This happens over and over again and it's why when you have a bulb go out that your flasher starts blinking slower because there's less current being pulled through the circuit slowing the heating.

The fact that you mentioned measuring 10.77 volts at some point in the circuit tells me that you have additional resistance. This is usually contact resistance such as you have found a bad ground. I can tell you from experience that 10.77 is rather low, you should not have that much voltage drop. About half a volt drop is the norm so assuming a 12.5 volt charge on the battery you should have around 12 volts.

This is just me guessing based on little information but I think you're on the right track chasing grounds and contact resistance.

[J&J]

An incandescent flasher is a current driven device basically what happens is the current flowing through the flasher relay heats up a bimetallic filament that bends into a banana from the heat breaking the circuit to the light bulbs...when the filament cools it straightens out and closes the contact again. This happens over and over again and it's why when you have a bulb go out that your flasher starts blinking slower because there's less current being pulled through the circuit slowing the heating.

The fact that you mentioned measuring 10.77 volts at some point in the circuit tells me that you have additional resistance. This is usually contact resistance such as you have found a bad ground. I can tell you from experience that 10.77 is rather low, you should not have that much voltage drop. About half a volt drop is the norm so assuming a 12.5 volt charge on the battery you should have around 12 volts.

This is just me guessing based on little information but I think you're on the right track chasing grounds and contact resistance.

I wasn't sure how much resistance there is in that circuit. It did seem low considering there are no actual resistors in it. However, I was using a variable DC power source to test the components and decided to test the flasher at 10.5V to make sure it would work at the questionable 10.77 and it did, hence my thinking that the voltage reading I took might be OK. So thanks for your experience there.

[J&J]

It was indeed a faulty wire. Looks almost "punctured" as if something pushed into it, down to the copper. It's in a tight spot and I couldn't really get a sense of what caused it, but there's a butt splice in that spot now so it should be protected well enough. The blinkers are working!

[Rubicon]

It was indeed a faulty wire. Looks almost "punctured" as if something pushed into it, down to the copper. It's in a tight spot and I couldn't really get a sense of what caused it, but there's a butt splice in that spot now so it should be protected well enough. The blinkers are working!

[NotThePainter]

I once lost the headlights completely in a Mazda 323 sedan. It had 100k miles and years of New England salt. There was no way I could afford a mechanic to trace it. So I got out the factory shop manual and tested every single connector. This included, if I recall, removing the steering wheel, so I could test the multi-function stalk. Everything looked good and tested good, but no lights.

So I started tracing wires from the headlights back to the firewall to the connector that wasn't in the factor shop manual!

Yeah, all green and corroded. I cut all that crap out and rewired it and I had lights again.

[Goat]

It was indeed a faulty wire. Looks almost "punctured" as if something pushed into it, down to the copper. It's in a tight spot and I couldn't really get a sense of what caused it!

That's caused by someone probing the circuit and using the probes to peirce the wire instead of running up to nearest connection and back probing. Welcome to the end result of that technique. Glad you found it.

[J&J]

That's caused by someone probing the circuit and using the probes to peirce the wire instead of running up to nearest connection and back probing. Welcome to the end result of that technique. Glad you found it.

Thanks. Just this morning I was describing it to a former mechanic co-worker and he said exactly that. I hadn't even considered that someone would do such a thing on purpose, but apparently it's not uncommon.

[Rubicon]

Thanks. Just this morning I was describing it to a former mechanic co-worker and he said exactly that. I hadn't even considered that someone would do such a thing on purpose, but apparently it's not uncommon.

Admittedly I have done it in the past, though I usually tried to tape or silicone seal it up. The issue is not so much the probing...it's more so the salt they slather on the roads up here :(