Stumped
 

Attached is a pic of the very detailed wiring diagram for our trucks. If you look at the drivers side marker light ground wire it doesnt show where it attaches to from the connector. It goes into the wiring on the truck but the ground to my front marker lights is not working and I do not know why it stopped. The second thing is that it shows a black ground wire coming from the back of the alternator and running to the voltage regulator and I do not have that wire on the back of my alternator.

Re: Stumped
 

Did both sides stop working or just one? Where it attaches depends on whether you are talking about stock type side marker with a 194 bulb and 2 wires, or an LED marker with more than 2 wires. If 194 type bulb it also depends on whether it blinks with the turn signal or just glows with headlight as in the stock configuration.

The ground wires at the alternator is a good idea, but not of paramount importance as the alternator is also grounded to the engine.

Re: Stumped
 

Hey, Greg, are you using stock bulbs or LED's?

Re: Stumped
 

I am using LEDS and they have been in there for a couple of years and worked fine until they didn't. I even took the LEDS out and tried 194s and still no lights. I took the bulb out ( both sides cause both sides are not working ) and used a test light and grounded it to the truck and the test light lit up when I touched the power side on the connector, thats why I figure its a ground wiring problem.

Re: Stumped
 

When it worked, if it blinked with the turn signal or just glows with headlight makes a difference on where it grounds.

If side marker blinked as a turn signal, and glowed steady when headlights are on, both wires from the side marker are connected to the wires going to the front blinker/running light. That would mean the side marker bulb does not really have a separate ground, it just gets ground through the wiring that goes to the front bulb. So check the front blinker and running light are working correctly with headlights on and with headlights off, and check ground to that assembly. Replace bulbs in front blinker/running light if needed.

In the configuration where the side marker blinks as a turn signal, and glows steady when headlights are on, the polarity to the bulb reverses when headlights are on, so you should have special non-polarity-dependent LED bulbs to work. The plain 194 bulbs do not care about polarity, but many LED bulbs do care. Front LED bulbs could make the situation more complex regarding whether or not the side marker bulbs work, if you have a conventional 2-prong 194-type socket with reversing polarity for the side marker light.

If the side marker just glowed with headlights and was not part of blinker system, then track the ground wire from the side marker to find where it grounds and make sure there's a good connection. If you have to unwrap and re-wrap the wires that is OK and you can get that non-adhesive black vinyl tape in a new roll from Amazon and redo it. It takes patience but no special skill, except my skills at knotting the tape at the end of the run are not the best so I end up using a small zip tie.

http://67-72chevytrucks.com/vboard/a...1&d=1465260730

http://67-72chevytrucks.com/vboard/a...1&d=1465260730

Re: Stumped
 

Thanks for the responses guys. This morning I took out the LED marker bulbs and put regular 194's back in and still no lights. I then pulled the front marker light LED's and put 1157's back in and then the side markers lit up. Then I put the side marker LED's back in and they still didn't light up. Also yes the front side markers and turn signals work interrmittently when the the left or right signal lights are used. I'm hoping I just need different side marjker LED bulbs so everything will work as it should.

Re: Stumped
 

Hi Bob.. Remember when we were talking when I was installing the front signal light LEDs. That was in in August /Sept of 2016. I'm thinking my marker light problem started then and i didnt notice it until one day last summer when i was using the truck just before dark and noticed I had no front marker lights.

Re: Stumped
 

In your case, the side markers ground through the front turn signal bulb filament. They won't work with an LED 1157 bulb. How about the back. Do you have 1157 LED's there?

Re: Stumped
 

We passed through Saskatoon on Friday the 11th. Too bad I didn't have time to stop in.

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I have 194 LRDS in the rear marker lights and they always work. I have LED taillights in the rear. I've attached a link for my rear tail lights.


http://www.uapac.com/antique/lightin...-assembly.html

Re: Stumped
 

This indicates you can't use 1157 type LED bulbs in the front blinker and have the side marker lights work. This is because LEDs are diodes and only conduct electricity in one direction.

So what do you think about just using conventional 1157's in the front?

or

You can wire the front markers in the marker-only configuration. They would no longer be dependent on the blinker wiring and would not be affected by whatever type of 1157 bulbs you want to use (LED or conventional). They would not blink. That is the way slightly earlier years worked anyway.

or

There are LED side marker assemblies that have 3 wire hookup, you may need that for the front side marker if it's important to you to have the blink function on the side marker.

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my 2 cents.

Re: Stumped
 

The rear marker lights are different because they aren't normally ever in a configuration that allows them to blink with turn signal. All they do is glow when headlights are on.

Re: Stumped
 

Thanks for the help. So are you saying if I get the 3 wire LED's I can run LED's in my signal light and side markers and they will blink intermittently? If so do you know here I can get 3 wire LED's as i havent been able to find them.

Re: Stumped
 

I think the 3 wire type are built into the marker instead of a separate bulb.

Here's one:
https://www.classicindustries.com/pr.../cp687201.html
It does not mention in the listing about 3-wire but I think it probably is.

Here is another thread where some folks are working on LED side markers, including 2 wire and 3 wire types:
http://67-72chevytrucks.com/vboard/s...d.php?t=677317

I believe the objective those guys had is to make the marker glow when headlights are on, and to glow brighter for the blinker signal. That's not the way I like mine, I prefer the marker to glow when headlights are on, and blink off and on when the turn signal is on. There is just one level of brightness on mine. In addition, I like the way conventional bulbs look, they are slow to come on and reach full brightness, and when they go off they fade off. I am considering adding LED bulbs just for the brake lights because it is advantageous for those to come on instantly.

I have seen posts where some board members custom make LED assemblies and sell to other members, but I did not bookmark those because I don't care too much for the bunch of separate glowing dots behind the lens. It makes the truck look to modern for my taste.

I have conventional bulbs, so I should excuse myself from further posts on this thread and let somebody who got everything going with LEDs to chime in and give all the details about exactly what to buy including part numbers and vendor.