Fog Light Grounding Questions

[PNewitt]

While researching for the book, I noticed that the wiring harness for the fog lights (same as the std. "GT" fog light wiring), that is wrapped with tape to the headlight harness--has a ground wire eyelet.

This eyelet is bolted to the bottom of the inside of the grille. The hole is to the left (as you stand at the front of the car) of the hood latch bracket on the core support. If you look down at the back of the grille, just left of center, it should be there, bolted to the grille (and a tab from the hood bracket for a good ground to the frame).

Do all of your cars have this? If so, what kind of bolt is used to secure it? It is a little (about 1/4") hex bolt, or phillips, or what? Does it have a nut on the underside, or is it like a sheet metal screw?

If someone could post a photo (from an original, unrestored car), that would be great.

For those of you with flickering or non-working fog lights, you might want to pull this eyelet from the grille, and wire brush (or emory board) the surfaces to make a better contact.

We're finding that a lot of the electrical problems are "bad ground" based. More on that later (for taillights).

p.s. anyone getting a little tingle shock on the door with your arm while driving, and the Marchals are turned on?

Thanks for your help,

Paul N.

 

[scott adams]

fog light ground

the only ground I can fined is 4 wires into two eyelets bolted with voltage regulater mounting bolt. two black and one black and one black with red stripe.

 

[rvrtrash]

I have 4 wires into 2 ring terminals at the bottom of the voltage regulator. Nothing that I can see or remember anywhere else on the front of the car.

Steve

 

[GTCSMustang]

Maybe I'm not looking in the right place, but I don't see anything like what is described on my HCS.

Scott

 

[PNewitt]

Nope, sorry, it's not anywhere near the voltage regulator. Go back to the front of the car, not in the engine bay.

Look at the grille. Then look at the backside of the grille, in front of the radiator. Just to the left of center, at the bottom of the grille, there will be a hole. This hole is shared with a tab underneath it, that is part of the hood latch bracket that is welded to the frame support (sometimes called the core support).

The fog light wiring harness is actually a separate little harness that is taped into the headlight/turn signals/marker lights harness at the factory. The fog light harness has two connectors (each with one female, one male). One wire comes from the fog light switch (grey?), and it runs all the way up to the front of the car, and ends up connected to one of the fog light connectors.

Anyway, the wire from the switch goes to one connector, then a ground wire is shared between each of the fog light connectors. In the middle of that wire is ONE eyelet, with each wire from each plug (making two wires into the eyelet). (still with me?)

The eyelet should be in the middle of both plugs that go to your Lucas or Marchal fog lights. This eyelet is about 3/8" diameter.

Have you found it? This is the eyelet, that is bolted to the bottom of the center, of the backside of the grille.

Right?

Thanks for looking....you might need a flashlight.

Paul N.

 

[Mosesatm]

A picture speaks a thousand words

 

[rvrtrash]

I think what everyone is saying Paul is that none of us has a ground wire there and the only ones we can find are at the voltage regulator. I looked again at my car just now, found the tab you are refering to and there is no ground wire there. Is it possible there was an engineering change that moved it? I know in some years Ford changed some things 2 or 3 times in a model year.
Steve

 

[gtcs1]

Paul,

Mine doesn't have that wire, the plug male connector is unused. The grille tab you refer too serves only in my case to hold the grille in place. The bolt of that tab doesn't look to have ever been removed.

I guess they changed that wiring concept. Anyway the lamps are grounded themselves by their metallic base (ground wire of my lamps are connected inside the lamp itself).

So this extra wire could have been redundant.

 

[di81977]

Ditto what Steve reported. My ground wires (including the grey fog light wire) are near the voltage regulator.

david

 

[PNewitt]

Sorry to send everyone on a wild goose chase. I'll have a digital photo in a few days.

"IF" the fog light ground wire is at the voltage regulator, could someone do a continuity check with a voltmeter (multimeter)? One lead at the male side of the fog light plug, and the other at the eyelet (wire in question) at the voltage regulator.

Thanks for getting a look at this.

Paul.

 

[scott adams]

I did continuity check the two black wires at voltage regulator is the ground.

 

[rvrtrash]

This hole is shared with a tab underneath it, that is part of the hood latch bracket that is welded to the frame support (sometimes called the core support).

Paul N.

Paul, my bracket assy is bolted to the frame/core support at the top and bottom-not welded. Is it possible that the car you are looking at had some front end damage at some time and the wiring was repaired in the manner you describe and the brackets welded in place instead of bolted?
Steve

 

[PNewitt]

Well, guess what? Here is an update.

I had a friend look at his brand new wiring harness that goes to the headlights, fog lights, side markers, and turn signals.

He looked at where the fog light ground eyelet is placed within the harness--that is, where it's taped next to.

Well, low and behold, it's right next to the voltage regulator plug. So, all of you are right. The ground for the fogs is mounted on the voltage regulator mounting screw.

As always--my sincerest thanks to everyone who went to the trouble to answer this question,

Paul.

 

[marie68csmustangs]

I don't know if this helps any, You can check any wiring diagrams and they should tell you were the grounds are and such... Just learing about those in school.

Marie

 

[PNewitt]

Hi Marie,

Thanks--and yes, that is true. Except in the diagrams, there is either a drawing of the eyelet all by itself, and you go:" OK...so where in da heck does THAT attach to ?"

Or...the ground is drawn as just three little lines that look like an upside-down pyramid.

Oh, yeah, that helps.

So, I ask from our great resource of owners to find out.

Thanks again,

Paul.