Left Turn Signal Won't Flash.

[84 S15 Jimmy 4x4]

Good afternoon,

Normally I wouldn't ask for your time with something this small. However, I'm driving 21 hours across the country in 5 days and realistically only have two days where I could work on it, so here I am.

Today my left turn signal stopped working. The right one works fine. The high beam light on the dash does not come on, so I assume it doesn't work either. When I use the left turn signal or turn my headlights on, the left dash light stays on, and the front and back external turn lights also come and stay on. Note that when I turn the hazards on, the dash lights blink appropriately, and so do the external lights for the most part. Specifically, the running light and the side marker light are supposed to alternate; however, on the left side, they work simultaneously. I have a video of this below to show what I mean:

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So yeah, it's not an issue with the bulbs because they can all light up. The flasher works fine for the right side so I assume that is also fine, however, obviously doesn't do anything for the left side. I was reading the shop manual for this truck and both the turn signal and high beam issues point to a short-to-ground. This would mean that there is unexposed wire making contact with the body somewhere, right? If you guys think this is the most likely issue, how would you go about finding this, and once I find it can I just duct tape it or something?

I truly know nothing when it comes to electrical so any and all feedback is appreciated, just note that I'm on a time crunch! If I can't get this resolved it is not the end of the world, I could just manually move the stock up and down to simulate the flashing but I'd rather not have to worry about stuff like that on my road trip.

Thanks,
Adam

 

[WP29P4A]

If there is a short to ground it would pop fuses. Have you changed any bulbs recently?

Some info on bulbs..........the base of the bulb is the ground, the little solder spot on the bottom of the bulb is the positive terminal/connection. If the bulb has two solder spots on the bottom it is a two filament bulb. The filament is what glows inside the bulb. Two filiment bulbs are used for brake lights and turn signals. If you get the bulbs mixed up and put the single filament bulb in a two filament socket it can do the odd things you are experiencing.

The fact that the bulbs light up ONLY tells you that they light up, it does not signify that they are in the correct sockets. You basically need to verify that each two filament bulb is in a sockets with two connections in the bottom of the socket.

The other thing that can cause the type of issues you are experiencing is bad grounds. The lights on your truck will be grounded in groups. The headlights and front turn signals should be grounded to a fender or the radiator support under the hood, check to make sure they are clean and tight, no rust or corrosion if near salt water. (Ocean)

There might also be a grounding location under the dash on the driver side close the e-brake, sometimes the headlight switch is grounded there.

It's also likely that there is a grounding location for the rear lights, close by. Sometimes behind one of the tail lights sometimes near the license plate light.

 

[Killer Bee]

I am having the same problem on my 1975 K10. All the turn signals work fine until I turn on the headlights . The the left doesn't work. I appreciate the advice and will try to track down the problem.

 

[BKING33]

You have a ground problem. Bad bulb and or socket connection is common.
There is a ground wire behind the taillamps. This is a common problem also.

 

[rusted nuts]

You have a ground problem. Bad bulb and or socket connection is common.
There is a ground wire behind the taillamps. This is a common problem also.

Yep, Bad ground I have seen them blink like RXR CROSSING lights