Parking light wiring problem with a '54 grill

[Hogger54]

I've got a strange issue with the drivers side parking light. Hopefully I explain this well enough.
No wiring kit, I'm doing my own.

So, I have isolated the power so that the only thing hot, is the parking light wire on the front of my truck. Power comes from Batt, through ammeter. Then other post on ammeter goes to alternator, and to my acc. switch. Then from acc. switch to headlight switch. headlight switch to fuse panel, then out to parking lights.
I have isolated left side and right side, and the problem still exists. Passenger side light works fine.

Here's the problem. My grill doesn't sit quite flush with the fender, about 3/4" out on the bottom corner. This is with the grill screwed and bolted in most positions except the bottom drivers side corner where the parking light is(a few screws removed).
With the bulb in the socket, the light works fine, but when I push the grill back in place against the fender, the light goes out. I'm pushing it back about 3/4 of an inch. Take the pressure off the grill, and the light comes back on. So, it must be grounding out on the fender right?? No, because the grill is already bolted and screwed to both fenders, and the radiator support.
Now when I use my voltmeter with positive to the parking light wire, and negative to the fender, it shows 12V. Push the grill against the fender(just like when the light goes out) it still shows 12V. And when I move the negative line to the hole in the grill for the parking light screw, it shows 12V. Push the grill against the fender and it drops down to about 0.

I'm using all new wires, new terminal strips, and new bulb sockets. I've tried a different type of guts in the socket, and it still does it.
I'm so confused. Any ideas??

[Hogger54]

I have found that if I have the parking light housing sitting loose off the grill, and I ground the light housing directly to the fender, the light works fine with the grill pushed against it or not.
Problem is, if I do it this way, aren't I still going to have some kind of drain on the battery from this mysterious "short"? Even though I have no wires going to, or near the grill.

[47 Fasttoys]

Alright, I'll take a shot here. My guess is when you are pushing the grill to the fender you are actually pulling the power lead away from the socket not allowing the 12 volts to reach the bulb. If you where in fact causing a short and grounding out the power lead you should see some spark at the very least and should blow a fuse. The fuses are designed to protect the wiring. Try running a small jumper wire from ground (frame) to the grill and check it that way if all works well it has something to do with flexing the grill.
Good luck, Rob

[mr48chev]

47 Fasttoys is correct in that you are loosing contact somewhere in the circuit when you push the grill back in where you want it.

Now you need to determine if you are loosing contact in the wire leading to the bulb or if you are loosing your ground contact between the grill and the fender.

Hook the ground lead of the test light or meter to a solid ground on the engine or away from the sheetmetal of the front end. See if you have power to the contact on the wire when you push the grill in place where you want it.

power there= bad ground between grill and fender. Create a good ground for the light

No power when grill pushed in= wire to light loosing contact somewhere. Then you need to backtrack on that wire to see where you are loosing contact.

Not sure about your truck as to if it is a freshly painted truck or one of the rust bucket "patina" trucks but either can create a problem with grounds and the majority of electrical issues were lights don't work are ground issues.

[Hogger54]

Originally Posted by mr48chev

Hook the ground lead of the test light or meter to a solid ground on the engine or away from the sheetmetal of the front end. See if you have power to the contact on the wire when you push the grill in place where you want it.

power there= bad ground between grill and fender. Create a good ground for the light.

I did a couple more tests, and spoke to a guy at work. And this is the case. So I'm going to run a ground to the frame for both parking lights. The grill is painted, and it's a metallic paint, so I think this could be contributing to the issue.

[OrrieG]

I had to change the sockets for my 59 TF for turn bulbs. When I did I soldered direct ground wire from the housing to a connector so the crimped connection between the socket and housing would not be the only ground. Like 48 said most problems with the old trucks are grounds, I also ran #4 wire from the bed near the back to the frame, cab to frame and radiator support to frame and and from frame to the firewall lug where the ground cable and engine ground are.