Which light is the tail light?

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Tozir

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So. I think I have some gremlins. My head lights work, and my turn signals front and rear work, my reverse light and brake lights work, but my tail lights and my side lights don't come on. Before I get to far into trying to figure a solution, I wanted to make sure the lights that do work are doing what they're supposed to be doing (I ask this because there is some sketchy work done to it).
1979 c10. The top light is the brake light and the turn signal, and the bottom is the reverse light. The side light doesn't come on, and I don't have a picture of it at the moment, but I also have a light on my fender that doesn't come on. It looks like a reflector, but there's a light behind it.

Are those where the lights are supposed to be, and what's the side light on the rear supposed to be?
Thanks for any help.

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theblindchicken

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Top bulb has two circuits. Low is the running light, high is brakes and turn signal.

Bottom bulb is reverse only.

Side wedge bulb is a running light as well.

Front fenders are also a running light.


Running lights come on only when the headlight switch is pulled out to the first position (running lights and dash lights) and at second position (turns on headlights). Otherwise they are off.
 

theblindchicken

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Also, having the housings painted green will actually cause your taillights to be considerably dimmer since it won't reflect as well as silver or chrome.
 

Craig 85

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Also, when the headlights or parking lights are on, the front side marker lights will flash on/off with the front turn signals. If the front flasher is on, the parking light will go out momentarily, then turn back on when the flasher is off.
 

chengny

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So. I think I have some gremlins. My head lights work, and my turn signals front and rear work, my reverse light and brake lights work, but my tail lights and my side lights don't come on. Before I get to far into trying to figure a solution, I wanted to make sure the lights that do work are doing what they're supposed to be doing (I ask this because there is some sketchy work done to it).
1979 c10. The top light is the brake light and the turn signal, and the bottom is the reverse light. The side light doesn't come on, and I don't have a picture of it at the moment, but I also have a light on my fender that doesn't come on. It looks like a reflector, but there's a light behind it.

Are those where the lights are supposed to be, and what's the side light on the rear supposed to be?
Thanks for any help.

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It appears that the tail/marker lighting circuit is out. That's the BRN 9 wiring as shown below:

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One of the two filaments in the top bulb is the tail light (the one that doesn't light up). And those little lights that point outward (as well as the lights on your fenders) are the marker lights. The license plate lights are probably out as well. All of these lamps are on the BRN 9 circuit.

If you haven't already, check that the fuse labeled TL/CTSY is good. BRN 9 also feeds the front parking/side marker lights. You didn't mention whether or not they work.

If the front parking lights work (H/L switch halfway out) and the tail lights do not, you have a broken or not properly connected lead in the rear lighting harness. Check the plug behind the bumper and inspect the harness. Usually a damaged harness will jump right out at you.

If - with the H/L switch in the parking lights position - you have neither front parking or tail lights, the problem is in the cab. If it isn't the fuse, maybe try a new/different H/L switch.

Do you have courtesy lighting - like when you open the door do the interior lights come on?
 

Tozir

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It appears that the tail/marker lighting circuit is out. That's the BRN 9 wiring as shown below:

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One of the two filaments in the top bulb is the tail light (the one that doesn't light up). And those little lights that point outward (as well as the lights on your fenders) are the marker lights. The license plate lights are probably out as well. All of these lamps are on the BRN 9 circuit.

If you haven't already, check that the fuse labeled TL/CTSY is good. BRN 9 also feeds the front parking/side marker lights. You didn't mention whether or not they work.

If the front parking lights work (H/L switch halfway out) and the tail lights do not, you have a broken or not properly connected lead in the rear lighting harness. Check the plug behind the bumper and inspect the harness. Usually a damaged harness will jump right out at you.

If - with the H/L switch in the parking lights position - you have neither front parking or tail lights, the problem is in the cab. If it isn't the fuse, maybe try a new/different H/L switch.

Do you have courtesy lighting - like when you open the door do the interior lights come on?
I haven't checked fuses yet, but I will when I get a bit of free time.
I don't know about the parking light. And by H/L switch, do you mean high/low? If so, I have the little knob I pull out to turn on the lights, then the floor pedal for brights. Would it still work with just pulling the knob half way?
And no, the side marker lights don't work.
And I don't have any interior lights.
But on that note, my dash lights don't work either.

Thank you for the reply! I don't know when I'll be able to get to anything on it. Working two jobs really takes it out of me.
 

spanky55amg

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I dont have access to a wiring diagram at work, but if you have no dash lights, and pulling the headlight switch out all the way or even half way for just parking lights, and your parking lights do not work, leads me to believe (((( once again without a wiring diagram to verify )))) that the switch has an internal failure or a fuse is blown. But, without the diagram, I wouldnt listen to me.
 

spanky55amg

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I haven't checked fuses yet, but I will when I get a bit of free time.
I don't know about the parking light. And by H/L switch, do you mean high/low? If so, I have the little knob I pull out to turn on the lights, then the floor pedal for brights. Would it still work with just pulling the knob half way?
And no, the side marker lights don't work.
And I don't have any interior lights.
But on that note, my dash lights don't work either.

Thank you for the reply! I don't know when I'll be able to get to anything on it. Working two jobs really takes it out of me.

H/L = Head light
 

Honky Kong jr

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So. I think I have some gremlins. My head lights work, and my turn signals front and rear work, my reverse light and brake lights work, but my tail lights and my side lights don't come on. Before I get to far into trying to figure a solution, I wanted to make sure the lights that do work are doing what they're supposed to be doing (I ask this because there is some sketchy work done to it).
1979 c10. The top light is the brake light and the turn signal, and the bottom is the reverse light. The side light doesn't come on, and I don't have a picture of it at the moment, but I also have a light on my fender that doesn't come on. It looks like a reflector, but there's a light behind it.

Are those where the lights are supposed to be, and what's the side light on the rear supposed to be?
Thanks for any help.

You must be registered for see images attach
I've used chrome tape in tail light housings it's better then anything your gonna spray in there to reflect light. If you get the metal tape it will last longer.
 

theblindchicken

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I've used chrome tape in tail light housings it's better then anything your gonna spray in there to reflect light. If you get the metal tape it will last longer.
Chrome tape or the aluminum ducting tape?
 

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