Front side marker lights?

[rsmarr1982]

Where are the front side marker lights grounded? They don't work with a bulb installed but when I ground my test light to the battery I get power plus previous owner had them individually grounded. In a hack way. I also found a light blue wire partially melted behind gauge cluster . It was coming from steering column to fuse panel area. Is this part of my problem? I wiring diagram I got from this site also shows my front two turn signal have blue and purple wires my truck has blue and brown. It's a 72 k20 BTW. Thanks for any help

[kwmech]

1972 the side markers are going to flash alternately with the front turn signals. Brown wire is power for the running lamps. The other wire, (usually ground without flash) can be wired to the flash wire going to the front. I converted my 68 to flash by doing just that.

[rsmarr1982]

Originally Posted by kwmech

1972 the side markers are going to flash alternately with the front turn signals. Brown wire is power for the running lamps. The other wire, (usually ground without flash) can be wired to the flash wire going to the front. I converted my 68 to flash by doing just that.

Ok so then where do the front lights grounded at?

[kwmech]

The front lamps ground through the housing where they bolt to the core support or the bumper

[tdangle]

what kwmech is saying is they ground thru the turn signal circuit. So when the turn signals are off the lights find a ground thru that circuit. When the turn signal flashes, the side marker light will also "flash" opposite of the front turn signal.

Hopefully this makes sense.

[rsmarr1982]

Ok I don't have a front bumper for it yet so I need to get one on there and get those lights on. Yhanks

[rsmarr1982]

I got the the front bumper lights hooked up and still the side marker only lights up when u ground it out. I made sure the light switch was bolted on so it it was grounded , I am lost!

[1968aj]

I have mine grounded to the screw that holds them on the truck.

[CaptRMW]

WOW I think this thread went straight down the crapper. Maybe Vette Vet could chime in and get to the bottom of this quickly. If you have original wiring with no modifications and are waiting for your side markers to flash you should go get at least a couple of 12 packs for refreshment while you wait...

[rsmarr1982]

Originally Posted by CaptRMW

WOW I think this thread went straight down the crapper. Maybe Vette Vet could chime in and get to the bottom of this quickly. If you have original wiring with no modifications and are waiting for your side markers to flash you should go get at least a couple of 12 packs for refreshment while you wait...

I'm just trying to get them to light up as parking lights. They will not light up a bulb period. But will light up a test light that's grounded . So I figured they are not getting ground .

[1968aj]

mine are parking lights only. they are tapped into front parking lights and grounded to screw that holds them to truck. mine is a 69 and never flashed.

[dmjlambert]

You can make them work as marker light only, or as blinker only, or as combo marker light and blinker. Details and schematic in this other thread. I don't recommend LED bulbs for this, just use regular 194 bulbs.
http://67-72chevytrucks.com/vboard/s...=707545&page=2

[jocko]

68s were marker lights only - 72s were designed to alternate when the turn signals or hazards are flashing or act as steady marker lights when lights are on otherwise. Clearly missing a ground. Yes, it SHOULD work. But if there's a bad ground anywhere in that circuit, it's gonna cause a problem somewhere. 1968aj is on the right track. Before you run a dedicated ground, you can confirm this is indeed where the bad ground is by temporarily putting a wire on one of the retention screws and screwing/wrapping it around a good known ground on the frame. Scuffing and metal-to-metal contact really does matter. Very frustrating, just went thru this on the back end of my truck. I had about 3 different problems out back simultaneously, so drilled a tiny hole in the back of the buckets, screwed a small terminal onto it, and routed it with the normal wiring harness, scuffed the frame in a spot, and bolted that #$%^& thing down. All problems solved... Yes extreme, yes hated to do that, but these trucks are notorious for ineffective grounding. Do you have grounding straps that connect your motor to you frame? Frame to body? Does your battery (-) cable go to the motor or to the rad support?

[SS Tim]

Originally Posted by rsmarr1982

... I wiring diagram I got from this site also shows my front two turn signal have blue and purple wires my truck has blue and brown. It's a 72 k20 BTW. Thanks for any help

Generic schematics are not the best help in the world. Try the factory 1972 truck chassis service manual pg 12-32 for the correct schematic.