I'm having issues with my '68 vert's parking lights. Everything works fine when I have the headlights on but when I put just the parking lights on they flutter on and off. Mainly off with a little flutter of on everyonce in a while. I have a new headlight switch installed already and it didn't change a thing. Almost like its got a bad ground but then why would they work when the headlights are on. Does anyone have any ideas on where to begin? I've looked at many wireing diagrams and they all show there is only one power wire going to the switch. Am I correct on that or is there a different power wire for just the parking light mode? Thanks.

 

another 68 vert... nice

as I see the wiring diagram, there is two sources of power for the parking lights

1. when the headlights are turned on they getpowerthrough the black/yellow wire from the lighting switch

2. but each parking light alsohas power (separate) coming from the turn signal switch (left = green/white, right =white/blue).

since the problem only occurs w/ the headlights off - maybe the turn signal switch is having problems, or both sides happen to have problems in the wires coming from the turn signal switch?

 

It won't be the turn signal wires causing the problems but may be the supply power to the switch. I can't remember but the switch may have a supply for the headlights and one for the parking lights. I would start buy checking the fuses for rust. Let us know..

 

Thanks guys. I'll take a look at the fuses. I have had a couple issues with them before. That was my thoughts on the blinkers too because the side marker lights don't blink in the front, just the front blinker lights, and my blinkers are working fine. The fact that the lights work fine with the headlights on make me think the grounds at the lights are good. Is there some other ground, like maybe to make the switch work in the parklight mode or something? Keep the ideas coming.
Chad

 

ok, the breakers for the headlights and all are built into the switch. The switch is new. It was doing it before I replaced it, which is why I replaced it. Is there some other fuse further down the line? Or a factory splice somewhere? I have had one of them go bad in the past.

 

i only see the two sources of power - from the headlight switch via the blk/yellow , and from the turn signal switch via (grn/wht and wht/blue) - only one ground per light regardless. Its a mystery that the power to them is steady through the headlight switch w/ the headlights on, but not steady through the headlight switch w/ just the parking lights on. Since you already replaced that part, the next i'd take a look at is the turn sig. switch - just thought that there may be something wrong allowing the power to trickle across intermittently , or that the wires (grn/wht, wht/blu) may have some damage from where they are bundled together and have worn through the insulation (though I haven't looked at mine to see if they are bundled together at any time from the switch to the lights, only going by the diagram)

do the parking lights work fine when you use your turn signals? are the rear lights or turn indicator lights doing anything odd too?

it looks like the emgcy warning flasher is hooked to the entire turn signal switch so that may be something too - but I would think only if all the lights were having a problem. Not much help, just brainstorming....

 

The rears act the same as the fronts. They work fine when all lights are on, but flicker when just in parking lights. The hazzards all work fine. I'll have to pull the steering wheel and see if something looks suspicious in there.

 

There are three sources of +12 for my 66 (i think the 68 is similar). The blk yellow turns to blk orange at the switch plug, comes directly from the alternator and is most likely the source for the headlights. It is un-fused.
There is a blue red that comes from the fuse block this is the inst panel lite circuit and probably has nothing to do with it either.
This leaves a blk yellow that comes from fuse block and is probably the source of your problem. check the fuse holder for looseness and corrossion. also monior the lights with a voltmeter when they're flutering to see if the voltage is the reason. If so, you can back track in the circuit tofind out why.
You could also ohm accross the removed switch to see what termals connect to each other when the switch is on, off, or in parking light position; then isolate to the voltage source for that set of terminals. The problem does not sound like a ground or a turn signal switch issue.(but electrical issues can be deceiving)