1947 ford parking light wiring issue
 

I've always been able to solve any wiring issues without much problem. However, this time I'm stumped. Another set of "eyes" sometimes helps.

1947 Ford tudor, I can not get the parking lights to function properly. The problem is when I wire the lights into the wiring harness following the color coded wire schematic and I pull the light switch out to the first notch for parking lights they (parking lights) work. When I pull the switch out all the way for headlights and hit the high beams the parking lights come on and no high beam.

I've checked the light switch at the dash, wired correctly. I have the yellow with black tracer from the pig tail on the switch hooked to the yellow with black tracer to the main harness. Some of the wire on the chassis is faded and hard to discern colors, I've checked their proper connections as best I can with a voltmeter.

All thoughts and ideas will be appreciated. I'm sure this is something obvious.

Seth

Re: 1947 ford parking light wiring issue
 

I'm a flathead novice but have read (told) that the dimmer switch can do "odd" things.


Paul in CT

Re: 1947 ford parking light wiring issue
 

The only common point that could cross up the connection would be the light switch itself, have you tried a different switch?

Re: 1947 ford parking light wiring issue
 

Dimmer switch, light switch or both?

I have thought about both of them. This car is an original, Dearborn type, with the exception of a repaint many years ago. So it retains what is probably the original light switch and possibly dimmer switch.

Re: 1947 ford parking light wiring issue
 

The headlight switch only delivers power to the dimmer switch in the headlight position. The dimmer switch toggles the power between the high or low beam. It sounds like you have the parking lights connected to the dimmer switch.

Re: 1947 ford parking light wiring issue
 

Possibly someone got the wires crossed up on the engine side of the firewall? The connections at the dimmer switch itself were soldered on.

Re: 1947 ford parking light wiring issue
 

Seth, before buying any parts check to see if everything is properly grounded. I had a similar thing happen years ago with taillights on a '46. I put on turn signals and when the left light would flash you could also see the right one flashing faintly. Chased the problem for 2-3 days. Finally decided to run an extra ground wire from the taillight housing to the frame on each light. Problem solved.
Go back over you wiring again. Since some of the wiring is faded there could also be a wire in the wrong spot. The dimmer switch should have nothing to do with the parking lights. They are separate circuits. A hot wire comes from the headlight switch to the dimmer and the other two posts on the dimmer go directly to the high and low beam of the headlights.
If you low beams are working I suspect there is a wire crossed at the bundle near the front fender or something crossed at the headlight switch.

Re: 1947 ford parking light wiring issue
 

I know this is not the case with later model Fords. It sounds like someone was in there before you.

Re: 1947 ford parking light wiring issue
 

Sounds like the guy who worked on my 40. Three different connectors and three different splices and three different gauges of wire in 10 feet of wire.

Re: 1947 ford parking light wiring issue
 

Light switch only. It seems to me the issue has to be in the switch or in the wiring connections. I would start with one wire at a time and see if you can follow it through the harness.

Re: 1947 ford parking light wiring issue
 

I'll start checking every connection with a volt meter and follow it down to the headlights and parking lamps. I'll have a friend operate the light switch while I check voltage.

Re: 1947 ford parking light wiring issue
 

Same as my '46. Agree with others, parking is separate circuit from headlights. You'll figure it out.

Re: 1947 ford parking light wiring issue
 

When you pull the switch out two clicks for headlights, do the low beams work? When you select high beams, does the dash high beam indicator work? Do you get tail lights for both high and low beam selection?

Re: 1947 ford parking light wiring issue
 

10-4 [emoji41]

Sent from my SM-G975U using Tapatalk

Re: 1947 ford parking light wiring issue
 

Yes, when I pull the light switch out for headlights the low and high beams work as long as I do not connect the parking light wires from the switch to the wiring harness under the dash. My tail lights and brake lights always function properly and by high beam indicator works as well.

Re: 1947 ford parking light wiring issue
 

Seth, I'm leaning towards a faulty headlight switch. Since it's the original switch (74 years old) there may be something worn or broken inside.

Re: 1947 ford parking light wiring issue
 

I'll take a good look at it. I might be able to come up with another switch locally in a V8 parts collection. I can swap it out and see what happens. Otherwise I'll get on each connection and switch position with a voltmeter and follow the issue from the dash switch to the front of the car. I've already done some of that troubleshooting.

Everything else works on this car, including the courtesy lights on the "B" pillars and with the help of the recent thread about the 42-48 clocks, I got the clock working again. The heater even works really well. It's a fun car to drive.

On a side note, was there a glove box light available in 1948? If not did Ford ever offer a glove box light?

Re: 1947 ford parking light wiring issue
 

Looking at the wiring schematic now it's pretty straight forward. Black with Yellow trace from the light switch, plugs into the Black/Yellow under the dash at the main harness, then plugs into the the Black/Yellow on the engine side of the firewall up to the parking lights or front crossover wire harness. I either have some wires crossed at the firewall or the light switch is bad. Still confused why when I hook the Black/Yellow together from the light switch into the Black/Yellow under the dash at the main harness, why the dimmer switch has anything to do with interfering with the parking lights?

Re: 1947 ford parking light wiring issue
 

I would try jumping power to each circuit one by one, bypassing the switch.

Re: 1947 ford parking light wiring issue
 

Seth, the only way the dimmer could be involved is in the wires at the front of the car. If the high beam wires are mixed up with the parking light wires the dimmer would send power to the parking lights rather than the high beams when the dimmer is switched from low to high.