Turn signal / Parking lights

[jkbrubaker]

Ok so I've been reading posts on electrical issues and it seems that there are many similarities but yet every one has some slightly different issue with there truck.

So here we go 65 c10 stepside. Been chasing some electrical ghosts and have it down to just one issue. All lights and turn signals work correctly for this year except for one. The parking light on the drivers side will not come on. Passenger side works fine, and all turn signals work fine. However when I pull the switch on for just the parking lights, the drivers side turn signal indicator on the dash comes on and stays illuminated all the time, but no parking light. When I put the turn signal on it flashes correctly and works all the way around.
So I was thinking that it was something from the fire wall out to the lights. Bought a new harness, and that made it worse. No parking lights at all, and no signals in the front. Ok back to square one.
I put it back the way it was and checked all the grounds, cleaned all the connections everything good there, and I believe all grounds are ok since I do have 1 parking light working on the passenger side.
Brake lights work fine, head lights work fine, interior light fine, license plate light ok, dash lights, and passenger side turn signal, perfect. Wiring under dash seems correct to the diagram, as well as on the switch itself. Looks to be correct from the factory. The only things that I can see that someone did was wire a kill switch off the ignition to prevent theft, but this doesn't appear to interfear with anything lights related.
This is not a huge deal, but bugs the crap out of me cause I want it right. So I'm looking for help, I have all the diagrams and have been over them so many times that I see them in my sleep. Maybe that's the problem I've been looking at them to much.
I'm kind of at a dead end because I just don't know what else to change aside from re-wiring the whole truck and I ask myself why, everything works fine except for 1 parking light.....Maybe I'm a bit OCD.
Anyway, any suggestions or help would be greatly appreciated.
Oh and I did replace the voltage regulator, when I replaced the battery and alternator. Did this when I bought the truck about 3 months ago.

[ray_mcavoy]

Originally Posted by jkbrubaker

All lights and turn signals work correctly for this year except for one. The parking light on the drivers side will not come on. Passenger side works fine, and all turn signals work fine. However when I pull the switch on for just the parking lights, the drivers side turn signal indicator on the dash comes on and stays illuminated all the time, but no parking light. When I put the turn signal on it flashes correctly and works all the way around.

Have you checked to make sure the bulb in the driver side is good? It's rare, but sometimes one filament can break and fall against the other one. That could prevent the parking light on that side from working as well as backfeed power to the turn signal indicator (the indicators are wired to the front turn signals).

Originally Posted by jkbrubaker

So I was thinking that it was something from the fire wall out to the lights. Bought a new harness, and that made it worse. No parking lights at all, and no signals in the front. Ok back to square one.

That's strange that the parking lights and front turn signals didn't work at all with the new harness. Does the connector on the new harness plug securely into place? And do the bulb sockets on the new harness snap securely into the light housings?

Originally Posted by jkbrubaker

I put it back the way it was and checked all the grounds, cleaned all the connections everything good there, and I believe all grounds are ok since I do have 1 parking light working on the passenger side.

Each side has it's own ground so just because one side works doesn't rule out a bad ground. The parking light & turn signal bulbs are grounded through the metal shell of the socket which in turn ground through the metal light housings and the screws that attach them to the hood.

A quick way to test the ground would be to run a temporary jumper wire from a known good ground (such as the negative battery post) to the metal shell of the non-working driver side bulb and see if that fixes the problem.

[Daman]

Bad bulb socket? That's what mine was.
It started after I put the new dash cluster in. I searched for hours and everything was turning out good so I was stumped. I finally pulled the cluster and checked with the new one. The old bulb filament was busted but sometimes worked. I reinstalled the new cluster and started to recheck the front. I wiggled the bulb and it lit up. Temp fix for the last couple days is a toothpick lodged in there until the new parts come in

[jkbrubaker]

Ray; I did check the bulbs in fact I actually bought 2 new bulbs just to make sure and then I switched them around to see if they worked in opposite sockets.

I thought that was odd also with the new harness. I was actually thinking that would solve my whole issue. I was really surprised when it didn't work. The bulb housing is actually plastic which I also thought was odd.

I didn't realize that each side has a ground since the diagram shows that the light are actually jumpered from one to the other. It looks on the diagram like there is only one ground but I may be looking at it wrong?

[jkbrubaker]

Daman; I was thinking that as well, that's what lead me to buy a new harness, but when that didn't work, and actually made it worse I got more stumped.

[ray_mcavoy]

Originally Posted by jkbrubaker

The bulb housing is actually plastic which I also thought was odd.

That shouldn't be a problem so long as the sockets have the little metal "gripper tangs" to hold the socket into the housing. That's where they make their ground connection.

Originally Posted by jkbrubaker

I didn't realize that each side has a ground since the diagram shows that the light are actually jumpered from one to the other. It looks on the diagram like there is only one ground but I may be looking at it wrong?

If you look closely at the diagrams, you should see a little ground symbol connected to each light housing.

The way they have the parking & turn signal wiring drawn on the factory diagrams is rather misleading though. It makes it appear as though the purple wire for the parking lights is joined (at the sockets) to the light & dark blue wires for the turn signals. In reality, each wire goes to a separate contact in the socket (and therefore to the separate filaments in each bulb). The purple wire that feeds power to the parking lights is the only one that is jumpered from one socket to the other.

[jkbrubaker]

Ray; Thanks for the info, sometimes another set of eyes on the info helps. I think I've been looking at that thing for way to long. I'll chech that wiring again and make sure its all correct. What your saying now makes me think it is a ground issue for the driver side. I'm thinking that since the new harness did not work at all then perhaps my issues are ground related.
Its currently back to its original state with wiring and since I have the least amount of problems with the old wiring I'll see what I can come up with this way.
Thanks again, I'll let you know if it works.

[jkbrubaker]

Well I think that I got it figured out. To my surprise the flasher module (the new flasher module) that I bought was bad.
I pulled it out of the fuse board over the weekend just by chance to check some other wiring. I turned the lights on and the parking light came right on.
So I went to pick up another new module at the autozone of course they are out of what I need, but I think this will solve the problem.
If not I'll be back