Turn Signal Issue That's Got Me Completely Stumped.

[Ellman605]

Hey all. So on this new Comanche I've gotten, turn signals don't work. The emergency flashers do, but the turn signals do not. First thing I did was try to swap the flashers under the dash. Got nothing. Checked fuse - good. Checked lights - good. 

 

Now, the part that has me beat, is the turn signals will light up ONLY if the brake lights are on (brake pedal depressed). They'll light up, won't flash though. But that's the only time they actually do anything. My main thought is the actual switch inside the steering column. Sound like a likely culprit?

[ComancheKid45]

That would be the next place to check in my books

[ftpiercecracker1]

check grounds? and when you say they come on only with brake lights, i assume that means when you press the pedal both your brake lights and indicators are illuminated together?

[Ellman605]

^ Correct. As I move the lever up and down, the light that is switched on is brighter, the other light is off. (As in, if I do a right signal as well as press the brake light, the left light turns off. Left signal with brake, right light is turned off)

[87manche1]

I would replace the front light sockets cheap and a good upgrade. Any trailer wiring?

[64 Cheyenne]

:agree:

[Ellman605]

Yup, there's some trailer wiring. What's being suggested? Forgive me, new to unibodies :)

[gogmorgo]

Being a unibody doesn't mean much in terms of wiring. Try disconnecting the trailer wiring. If it solves the issue, then you've likely got a short in it somewhere. Also, it seems to be pretty common for a diy trailer harness to be patched right into the taillights, and usually pretty badly at that, which can cause all kinds of issues when something fails.

Another thing to check is to make sure you've got all the right bulbs. A single-filament bulb in a double-filament socket can wreak havoc.

[Myron]

 I'm having a similar problem. Neither my signals or flashers worked when I got my truck. I checked the fuses and the one for the hazards looked burnt. I wiggled in the slot and my hazards came on. Now, when I turn my running lights on my signals come on as well, don't flash just come on. When I turn one of them on, it goes off? I'm thinking the clutch master leaked out and messed something up?

[Ellman605]

 I'm having a similar problem. Neither my signals or flashers worked when I got my truck. I checked the fuses and the one for the hazards looked burnt. I wiggled in the slot and my hazards came on. Now, when I turn my running lights on my signals come on as well, don't flash just come on. When I turn one of them on, it goes off? I'm thinking the clutch master leaked out and messed something up?

That to me sounds like the flasher is bad. If your hazards work, swap the two silver cylinders that are in the fuse panel. Ones on the bottom left ones on the top right. They're the flashers that control....you know....the flashing of the lights.

[cruiser54]

 

 I'm having a similar problem. Neither my signals or flashers worked when I got my truck. I checked the fuses and the one for the hazards looked burnt. I wiggled in the slot and my hazards came on. Now, when I turn my running lights on my signals come on as well, don't flash just come on. When I turn one of them on, it goes off? I'm thinking the clutch master leaked out and messed something up?

That to me sounds like the flasher is bad. If your hazards work, swap the two silver cylinders that are in the fuse panel. Ones on the bottom left ones on the top right. They're the flashers that control....you know....the flashing of the lights.

 

Re-read post #1.

 

[Ellman605]

 

 

 I'm having a similar problem. Neither my signals or flashers worked when I got my truck. I checked the fuses and the one for the hazards looked burnt. I wiggled in the slot and my hazards came on. Now, when I turn my running lights on my signals come on as well, don't flash just come on. When I turn one of them on, it goes off? I'm thinking the clutch master leaked out and messed something up?

That to me sounds like the flasher is bad. If your hazards work, swap the two silver cylinders that are in the fuse panel. Ones on the bottom left ones on the top right. They're the flashers that control....you know....the flashing of the lights.

 

Re-read post #1.

 

I know what youre saying haha. No, I've tested the flashers. My flashers were bad. replaced them both. The issue is they still won't flash, and they only react at all if the brake lights are on

[Myron]

I swapped the flashers and now my signals work. They still come on with my running lights. They will flash just extremely slowly. (Too slow for other drivers to understand that I'm turning) I'm thinking it's grounded out somewhere?

[ftpiercecracker1]

Have you cleaned the connector that couples the HL harness to the rest of the harness?

[Myron]

I completely replaced the headlight harness. The sockets had been engineered together so many times there wasn't much wire left connecting them, it looked like a row of crimps and electrical tape. Also, the sockets themselves were grounded out which probably explains why my flashers came on with my lights. The connector was filthy so I cleaned it thoroughly while I could get to it easily. I replaced the sockets and now only the right side flasher stays on with the lights. The thing that I am finding strange is that if I remove the bulb, the light inside the cab no longer comes on with the lights? The running light doesn't work on that socket either, only the flasher. I'm about tired of lighting issues at this point.

[Myron]

I put another new socket in and now my lights work :banana: . I checked with my flashers on and noticed something odd tho. My passenger side flashers opposite my driver side. To clarify, rather than flashing together, it comes on when the rest go out. It looks strange with my flashers on lol. It isn't really an issue. However, I see it being looked into a little closer before long.

[gogmorgo]

You may find you want to look at that sooner than later. Alternating hazard lights are no longer hazard lights, they're now emergency vehicle lights, depending on jurisdiction. You could end up with a fine. Also, if it's a short you could fry other components without having the 4-ways on, or even set your truck on fire.

Check the wiring. If you connected a couple wires together you shouldn't have, or didn't connect a couple you should have, it could do this. Also check the grounds. Had the alternating hazards thing happen to me a few years ago when putting together a trailer plug adapter, going from 7-pin to 4-pin. It was a few years ago, and there was enough going on that night (as is the case when a tow vehicle craps out in the middle of nowhere at 1 am) that my memory as to what was wrong is too foggy.

Could also be a bad flasher, but probably not, given you said you swapped them (assuming for new ones, although new parts have been known to be bad) and it happened when you redid the wiring. If you did replace both flashers, swap them around and see what happens. If no change it's wiring issues.

[Myron]

I dug into it tonight and made it worse. The only thing that makes sense is that one or more of my sockets are bad on my passenger side. The taillight on that side is a glob of "redneckitry". The truck was either wrecked or got a little too close to something in the woods now has a conglomeration of things that make up the lens. With my flashers on, the top and bottom lights flash opposite on that side. Also, one flashes bright and the other dim. On top of that when I press my brakes the lights quit flashing??? Maybe by the end of this we will have figured out the answer to the ellman605's original problem lol.

[Myron]

My truck had an 1157 in one socket and a 2057 in the other on the passenger side. I replaced both with 2057 since one came apart when I took it out and the other had a burnt filament. Now the flashers all work properly... at least for a few minutes. Now my brake lights don't work at all. Neither do my hazards. But, my turn signals work fine??? I took apart the socket that had a burnt bulb in it and cleaned it as it appeared to be the culprit. Nope. Unplugged the tail light harness altogether and still nothing. I'm still thinking the fuse box is to blame. About halfway through cleaning it rain started pouring on me. I guess it'll wait until tomorrow.

[ftpiercecracker1]

The top and middle bulbs in your tail lights should have two filaments each, just FYI if you didnt already know. Your reverse lights should only have one filament.

[Myron]

The top and middle bulbs in your tail lights should have two filaments each, just FYI if you didnt already know. Your reverse lights should only have one filament.

Yes, but the 1157 and 2057 are different dual element bulbs. I don't know exactly what the difference is seeing as they both were in a socket designed for a 2057? My guess is the hotter prong is opposite on them. Like if you put the wrong one in the running light would be brighter than the turn signal? I cleaned the fuse panel the best I could and put lithium grease on the fuses to help them get a better connection in that corroded mess. Still no brake lights. I checked the pedal sensor, voltage at the sensor, and voltage at the fuse panel. All checked out fine. I'm going to check voltage at the taillight harness next chance I get unless someone has a better idea. Also looks like I'm driving my Wrangler until this gets sorted out. I haven't checked the gas mileage on it because it rarely sees the street. I'm guessing under 10MPG and unnecessary wear on my 38"TSL's doesn't have me jumping for joy to say the least.

[ftpiercecracker1]

Test for 12v at your brake light switch, if you got it, use a jumper to connect the two wires in the brake light switch. Check and see if you have lights then, if not you've got problems between the switch and the light socket.

[Myron]

My apologies if I was unclear. I have checked voltage at the fuse, voltage at the pedal switch, and continuity at the switch when the pedal was depressed. All checked fine. I downloaded the 1988 MJ Electrical Troubleshooting manual and by following it's suggestions have came to this conclusion. My turn/hazard switch assembly is defective. I have a donor from my other 88 Comanche (that's getting the 97+ swap) and am currently working on getting it out. Has anyone had to replace this on account of the brake lights not working before? Also, Ellman605, have you downloaded this manual or checked this part? 

[gogmorgo]

I just went to swap out my dad's reverse lights today and in the process broke the brake light. It was a 2057, but the only place in town that sold bulbs didn't have them, so I got the 1157's, which seemed to be the closest match. And they worked alright.

Your post prompted me to do some googling, and it turns out that the two are almost identical, but the 1157 is slightly brighter and runs slightly hotter, and doesn't last quite as long.

[Myron]

So this has me stumped now. I started thinking since I checked the voltage without the connector plugged in it may not have completed the circuit. Thus explaining why I'm not seeing voltage on the other side of the turn/hazard switch assembly. Checking voltage at C156: Terminal P has 12v IF IT IS NOT PLUGGED IN, 0v otherwise. Terminal N has 0v regardless. I stumbled upon this trying to figure out why I couldn't get a reading from the back side of the connector. I plugged in my other steering column, it has a known good switch, and it does the same thing. I've seen some strange things before. But this makes no sense. Any thoughts?