Driver side turn signal not working, Weird voltage issue... i think? Options

[Noahwhite2014]

SO my driver side front turn signal is acting up. Ive tried swapping bulbs, same issue. Tried swapping bulb holders, the issue persists. So i know its probably the wiring now... So i pulled out the voltmeter... Stuck the ground into the ground wire pin on the harness plug, and the positive into the left side positive pin on the harness plug (the locking mechanism is at the top, i couldn't see the wire color since it was dark) and i got 25.6V DC... This is supposed to be the DRL light on the corners. I'm not sure if it is supposed to be 25v... but i assume it shouldn't. I didnt have time to test the other side to see if it was also 25v

Then i kept the ground in the same middle pin and the positive to the right side pin on the harness, nothing happened so i assumed it was the turn signal. Popped on the turn signal and got the hyper flash since there was no bulb in. But anyway i pulled 12v off that. Couldn't really read accurately since it was going on and off so quick that the voltmeter hardly had time to read it.

So based off the voltages (assuming the 25v is correct for DRLs...) I SHOULD be getting a DRL and turn signal. BUT i only get a DRL, the turn signal shuts off the DRL light when it is supposed to flash. When the DRLs are off and i try to signal, The DRL filament will come on instead of the turn signal filament (so its dim). I forget to test the voltage on the DRL pin and the turn signal pin with the DRL's off.


Anyone had this issue before? Any ideas on what else to test?

[Box]

Something somewhere is off, you shouldn't exceed the 12-14V of the car's electrical system. The only way for that to happen would be for two sources of 12V to be in series, i.e. negative to positive to negative to positive. Though in a car you have a common ground. So it sounds like the positive of the high filament is being fed into the ground for some reason.

[Box]

Though that should also cause a short, but maybe if it's isolated to the one section of harness it wouldn't cause issues elsewhere.

[rapid36]

SO my driver side front turn signal is acting up. Ive tried swapping bulbs, same issue. Tried swapping bulb holders, the issue persists. So i know its probably the wiring now... So i pulled out the voltmeter... Stuck the ground into the ground wire pin on the harness plug, and the positive into the left side positive pin on the harness plug (the locking mechanism is at the top, i couldn't see the wire color since it was dark) and i got 25.6V DC... This is supposed to be the DRL light on the corners. I'm not sure if it is supposed to be 25v... but i assume it shouldn't. I didnt have time to test the other side to see if it was also 25v

Then i kept the ground in the same middle pin and the positive to the right side pin on the harness, nothing happened so i assumed it was the turn signal. Popped on the turn signal and got the hyper flash since there was no bulb in. But anyway i pulled 12v off that. Couldn't really read accurately since it was going on and off so quick that the voltmeter hardly had time to read it.

So based off the voltages (assuming the 25v is correct for DRLs...) I SHOULD be getting a DRL and turn signal. BUT i only get a DRL, the turn signal shuts off the DRL light when it is supposed to flash. When the DRLs are off and i try to signal, The DRL filament will come on instead of the turn signal filament (so its dim). I forget to test the voltage on the DRL pin and the turn signal pin with the DRL's off.


Anyone had this issue before? Any ideas on what else to test?

I haven't had this issue before but you can try checking the wiring behind the dash. There are wires for the turn signals by the hazard harness. It's the plug that plugs into your hazards switch. Check out the wiring there. See if there is anything that looks abnormal.

[Noahwhite2014]

Something somewhere is off, you shouldn't exceed the 12-14V of the car's electrical system. The only way for that to happen would be for two sources of 12V to be in series, i.e. negative to positive to negative to positive. Though in a car you have a common ground. So it sounds like the positive of the high filament is being fed into the ground for some reason.

I kind of figured that, so the 25 volts went away today, I did wash the car yesterday so some ground somewhere might be breaking and at the same time a positive 12v is shorting to the broken ground somewhere and feeding into the drl...? Idk if that makes sense but it did in my head. I'll go trace wires and clean grounds on my next day off

I'm thinking that possibly the two positives the drl and the turn signals are connecting somewhere because I can figure out why the light would turn off when receiving at least 12v to both positives and its getting a solid ground.

Electricity on paper always seems easier than what I deal with in real world situations...

Thanks for the replies guys, hopefully I can figure this out soon because right now I've got the bulb hooked up to a switch in the car with and inline fuse and that's on the battery. So to turn left I'm literally pressing a momentary switch to signal to cars in the front. I know it's probably a bad idea, but the cops here pull you over for dumb things like not using turn signals while someone flies by at 90 in a 45mph zone

[Noahwhite2014]

SO my driver side front turn signal is acting up. Ive tried swapping bulbs, same issue. Tried swapping bulb holders, the issue persists. So i know its probably the wiring now... So i pulled out the voltmeter... Stuck the ground into the ground wire pin on the harness plug, and the positive into the left side positive pin on the harness plug (the locking mechanism is at the top, i couldn't see the wire color since it was dark) and i got 25.6V DC... This is supposed to be the DRL light on the corners. I'm not sure if it is supposed to be 25v... but i assume it shouldn't. I didnt have time to test the other side to see if it was also 25v

Then i kept the ground in the same middle pin and the positive to the right side pin on the harness, nothing happened so i assumed it was the turn signal. Popped on the turn signal and got the hyper flash since there was no bulb in. But anyway i pulled 12v off that. Couldn't really read accurately since it was going on and off so quick that the voltmeter hardly had time to read it.

So based off the voltages (assuming the 25v is correct for DRLs...) I SHOULD be getting a DRL and turn signal. BUT i only get a DRL, the turn signal shuts off the DRL light when it is supposed to flash. When the DRLs are off and i try to signal, The DRL filament will come on instead of the turn signal filament (so its dim). I forget to test the voltage on the DRL pin and the turn signal pin with the DRL's off.


Anyone had this issue before? Any ideas on what else to test?

I haven't had this issue before but you can try checking the wiring behind the dash. There are wires for the turn signals by the hazard harness. It's the plug that plugs into your hazards switch. Check out the wiring there. See if there is anything that looks abnormal.

Good idea, now that I think of it I pulled out my center console cover to check wires going to my head unit and i do recall man handling the front plastic piece without unplugging any wires from it... Thanks for the idea!

[Noahwhite2014]

Solved! The turn signal pin on the harness side had the turn signal pin which broke off from the bulb holder side and stuck in the plug just barely bridging the turn signal positive to the middle ground pin. Further down the workmy harness there were some bite marks from a rat on all the turn signal wires. I assume those were how I somehow got 25v and the short in the harness plug was how my turn signal wasn't working...? Or the combination lol still don't know, but it's fixed thanks for all the help again guys!

[Box]

WOOOOO I WAS RIGHT!!!!! I mean, congrats!

[Noahwhite2014]

WOOOOO I WAS RIGHT!!!!! I mean, congrats!

Yup haha I still want some electronic wiring guru to explain to me how I could get 25v from a 12v battery. As far as I know, you can't wire a single battery in series with itself.... That would just be a short... Lol

And as far as I know I don't have any voltage doubling transformers in my car...

This post has been edited by Noahwhite2014: Jan 20, 2015 - 1:39 AM

[rapid36]

WOOOOO I WAS RIGHT!!!!! I mean, congrats!

Yup haha I still want some electronic wiring guru to explain to me how I could get 25v from a 12v battery. As far as I know, you can't wire a single battery in series with itself.... That would just be a short... Lol

And as far as I know I don't have any voltage doubling transformers in my car...

you mentioned rat bites, i suspect that the rats put voltage transformers in your car.

[Box]

I'm officially losing my mind, I had a nice detailed post and it didn't post apparently... Long story short, circuits make the power sources independent. Voltage is potential energy and can be manipulated depending on how it's configured. So inside of a circuit, for example your front marker light, you have a common ground and two sources of 12V. Should one cross into the common ground when both circuits are sent power it makes a connection in series and doubles the voltage.

[Noahwhite2014]

I'm officially losing my mind, I had a nice detailed post and it didn't post apparently... Long story short, circuits make the power sources independent. Voltage is potential energy and can be manipulated depending on how it's configured. So inside of a circuit, for example your front marker light, you have a common ground and two sources of 12V. Should one cross into the common ground when both circuits are sent power it makes a connection in series and doubles the voltage.

Thats what I was thinking, lol I did a little experiment before reading your post. I was trying to double the voltage of a 1.5v battery. Basically I got two wires on both the positive and negative end of the battery holder. Hooked up one pair of wire leads to it. Of course it said 1.54v +-.02v. Then I shorted the other pair of wires quickly. Voltage changed, but it was minor. Did it again, and I got 0. Then I did it multiple times quickly and got it to change a bit lower, some a bit higher. But not much

I appreciate the replies