The Ford Barn

Bob Bidonde · 10-09-2014, 09:53 AM

Body Grounding

The Model A has a single wire electrical system, so the body, frame and running gear need to behave like a second wire to the battery / generator. It is well known to install an extra ground cable to the transmission, but rarely is there any mention of assuring the body is well grounded.

Take both of the forward most cowl-to-frame bolts out, and wire brush them bare. Wire brush bare the bottom of the frame rails, and the top of the cowl structures around the bolts holes. Reinstall the bolts, and after tightening them, overcoat the visible bare areas with epoxy paint.

Tail Light Crossover Harness

I recently installed a main wiring harness with integral turn signal wiring. For reference, it is the same as Bratton's 20422. I bought this harness over-the-counter, so I did not read any literature beforehand.

My Model A has 2 tail lights, and its cowl lights will be the front turn signals. You need to know your setup before buying the harness as there are several configurations of harness to choose from.

The surprise to me was that, if you say to the dealer that your car has 2 tail lights, then the tail light crossover harness is built-into main harness with integral tail lights. You do not need to purchase the crossover harness separately! This is a $17 cost avoidance.

Harness Braiding

The cloth braiding on the Model A's wiring harnesses will quickly fade to gray in direct sunlight. So if you are a shade tree mechanic, it is a good idea to put the harnesses in near the end of a restoration. The body and hood will keep the sunlight off of the wiring.

Tail Light Wire Support

The green & black wires that protrude from the tail light were originally clamped to the rear fender support bracket. A clip, smaller than those used on the frame, clamps the both wires to the rear flange of the fender support.

Lets keep this thread going with your ideas and experiences.

P.S. · 10-09-2014, 10:26 AM

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Quote:

Originally Posted by Bob Bidonde

............. If your Model A has been restored, it's likely there is so much paint on the belt rail that the dash light has poor ground continuity (high resistance), so the bulb burns too bright.

.

Bwahahahaa!!! Not a chance. Having a poor ground connection means a dim bulb, not an overly bright bulb.

10-09-2014, 09:53 AM	#1
Bob Bidonde Senior Member Join Date: May 2010 Location: Long Island, NY Posts: 3,463	Wiring Trivia Body Grounding The Model A has a single wire electrical system, so the body, frame and running gear need to behave like a second wire to the battery / generator. It is well known to install an extra ground cable to the transmission, but rarely is there any mention of assuring the body is well grounded. Take both of the forward most cowl-to-frame bolts out, and wire brush them bare. Wire brush bare the bottom of the frame rails, and the top of the cowl structures around the bolts holes. Reinstall the bolts, and after tightening them, overcoat the visible bare areas with epoxy paint. Tail Light Crossover Harness I recently installed a main wiring harness with integral turn signal wiring. For reference, it is the same as Bratton's 20422. I bought this harness over-the-counter, so I did not read any literature beforehand. My Model A has 2 tail lights, and its cowl lights will be the front turn signals. You need to know your setup before buying the harness as there are several configurations of harness to choose from. The surprise to me was that, if you say to the dealer that your car has 2 tail lights, then the tail light crossover harness is built-into main harness with integral tail lights. You do not need to purchase the crossover harness separately! This is a $17 cost avoidance. Harness Braiding The cloth braiding on the Model A's wiring harnesses will quickly fade to gray in direct sunlight. So if you are a shade tree mechanic, it is a good idea to put the harnesses in near the end of a restoration. The body and hood will keep the sunlight off of the wiring. Tail Light Wire Support The green & black wires that protrude from the tail light were originally clamped to the rear fender support bracket. A clip, smaller than those used on the frame, clamps the both wires to the rear flange of the fender support. Lets keep this thread going with your ideas and experiences. __________________ Bob Bidonde Last edited by Bob Bidonde; 10-09-2014 at 05:04 PM.