Lighting issues

[Mckay417]

Any advice, tips or suggestions would be appreciated as we are completely lost and dont know what steps to take next. Me and my boyfriend purchased a 1931 model a from my grandparents. Garage kept since sometime in the 60's. Original wiring harness was pretty bad and cut up so it got trashed. Bought a new wiring harness and kept the original housing. After many of hours of trying to figure out where wires go, what needs grounded, having a lot of issues with sparking and things getting hot when battery got hooked up. We finally got rid of the sparking and got lights to work. But the harness housing kept popping loose when turning the switch, so we replaced the housing with a new one and have not been able to get lights since. We have spent many hours and nights working on it trying to figure out what went wrong just by replacing the housing. The only thing i see that may be an issue is on the black disk on the harness the circle horn piece that connects to the horn rod is slightly bent where i think we tried to pull the horn wire loose and realized it didnt come off, but it still looks like it should make connection. Everything is grounded and hooked up like it should be other then tail lights but those were not hooked up when we first got lights. Like i said any help is appreciated.

[Mike Peters]

I think you refer to this as a 'housing'? We call this the light switch. the slots and raised areas need to correspond when assembling. It will only go together one way. Don't force anything. Your light switch lever on your steering wheel must be in the 6 O'clock position when off. Dim headlights will be one click counter clockwise. Bright will be two clicks counterclockwise. Park lights are one click clockwise. The light switch should work freely and not turn when you turn the steering wheel.
It would help us if you could take some photos to show us what you are having trouble with.

[Joe K]

The wiring diagram of the car should help. See https://lesmodela.files.wordpress.co...ng-diagram.pdf

Note the wire colors match the diagram, and the switch plate is "corresponded" to agree with the description above.

Also note that many have problems with wiring harnesses bought from the vendors since the "bullet ends" are crimped in place: original bullet ends were brass and soldered on. The modern replacement "couplers" that take these bullet ends are pretty good but repop bullet ends are not held reliably or consistently.

Also note that many have problems with the switch plate coming with the new harnesses - something about the brass contacts which an original or repop switch contactor cannot or won't follow.

Also note that many have had problems with repop bulb sockets. The plastic these are made of now are wont to melt and the impresses on the metal part are not made deep enough to align correctly with the sleeves in the headlamp reflectors or the sleeve at the connector fitting.

Also note that reflectors themselves are frequently found with a non-parabolic curve and won't reflect properly. Also the ferrules that take the sockets can "turn" and make the socket an incorrect orientation to the reflector.

There are a whole host of problems with the repop parts for the headlights. Mostly coming from people working from what they think the parts should be and NOT what the Ford parts drawings show. Also quality control is an issue.

Additionally some cars were "early" in Ford production (Type H headlights) and these have a distinctly different wiring diagram. Look at the feelers on the switch. If there are four four feelers/contacts, yours is early and can't be mated with the available switch plates and won't agree with the wiring diagram. If there are three contacts then everything above applies.

As originally designed the Ford switch/headlight system was made with quality parts, and would go together only one way. Orientations and tolerences were maintained and everything went together and worked on the first try.

Today we're not nearly that lucky, or intelligent, or skilled to make it happen.

Sort of like putting a man on the moon?

Joe K

[rotorwrench]

The Ford model A vehicles are very good to learn basic automotive wiring systems and circuits since they are so simple. They were actually a little too simple since they had no circuit protection originally. Most folks add a fuse at the starter connection to protect the wiring. Most all automotive systems use the physical connection of electrical components to the frame of the car for ground since it is a very important part of the of each circuit. This way most all circuits only use a power wire to function each electrical component. With this being said, it is very important that all these electrical components have a clear ground path back to the frame of the car. A good example is how the headlamps and horn are installed. The ground path has to go through the component to the headlight bar then on to the fender and fender brace. The fender and brace both connect to the frame. All these connections can be problematic if there is any corrosion or crud blocking the ground pathway. Fiberglass fenders are out there but not as likely on a restoration from the early 60s. Fiberglass is not a ground path so you can see how that might be important for tail lamps, etc.

You need good conductor pathways and ground pathways. That light switch has to have all the correct parts for reliable function as was indicated previously. The bale has to secure it well to the bottom of the steering column too. For 1928 thru 31, this was an effective piece of technology when compared to the model T cars. It kept most of the wiring all in one place but the area it was placed in was a swampy area so it wasn't the best place to put a switch. Ford used that location for the light switch clear up to 1939 with good results as long as it was maintained in good condition. A crack in the steering box horn wire carry through tube can leak steering gear oil right into the switch housing and it does happen now and then.

Make sure all your terminal connections are as clean and tight as you can get them. Loose connections create resistance and get hot. This heat can melt things like reproduction terminal boxes and the vinyl covering on the reproduction wiring. Use as much original type equipment as you can but make sure it all functions as it should. As was mentioned, a lot of reproduction electrical system parts are not made as well as the OEM stuff and this can cause a lot of problems down the road.

[Bob C]

There were some problems with the contact plate on the wiring looms for awhile.
Also make sure you have the correct ends for the headlight wires.


Bob

[rotorwrench]

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That definitely helps with one of the repro part issues. A lot the parts like the disk were likely made from reinforced bakelite back in the day. The stuff could take a lot more of a beating than the modern plastics used in the reproduction parts. It's too bad it doesn't last forever but I imagine there are a few original parts like this still in service.

[lorenallen]

I recently rewired my 31 Model A Cabriolet and it was a challenge. Let's start by saying that I worked as an electrical technician for over 30 years so I had a lot of wiring experience. If the wiring harness you bought has directional signal wires then it will not fit in an old style switch housing. I bought a new style switch from Brattons and it did not work from the beginning. I called my mechanic who has more 30 years experience and he could not get the Brattons switch to work. He had a used switch assembly and that worked well from the beginning. It is quite a challenge to feed the wiring harness thru the lower opening in the switch assembly. I would suggest you contact a local club to see if you can get some help from someone with experience. My new wiring harness works very well and it included new prewired directional signal wiring. If you are rewiring the car it is a good time to add directional signal wiring. Also I would change the stop light switch for a high quality one with bushings in the switch. Good luck with your car and I hope you can solve the problems.

[PalAl]

Originally Posted by Mike Peters

I think you refer to this as a 'housing'? We call this the light switch. the slots and raised areas need to correspond when assembling. It will only go together one way. Don't force anything. Your light switch lever on your steering wheel must be in the 6 O'clock position when off. Dim headlights will be one click counter clockwise. Bright will be two clicks counterclockwise. Park lights are one click clockwise. The light switch should work freely and not turn when you turn the steering wheel.
It would help us if you could take some photos to show us what you are having trouble with.

Mike I thought it was... 6 o'clock is the off position, 7 o'clock is the running lights and then 5 o'clock is low beams and 4 o'clock is high beams.

[Mike Peters]

Al: Maybe we are both wrong! The photo is from the Les Andrews "Troubleshooting and diagnostics", the 'blue book'. Les says the first light switch position to the right is bright lights, and second is dim lights. I didn't know that. I've always installed the headlight bulbs in the sockets to run dim first, and bright second to the right.
On your car, if what you have works for you, then leave it. Otherwise, you can change the wires around inside your headlights.

[Joe K]

The wiring diagram I referenced in an earlier post appears to have the light switch connections shown incorrectly. The three contacts are sequential and "in line."

But this is not the case in function. The switch contactor when in its normal position of center - off, "spans" the three contacts, making contact with none of them. From this initial position the switch can be turned left for "park," Right 1 for "dim" and Right 2 for "bright."

I checked the diagram above against Victor Page's diagram in his book The Ford Model A Car (1929ish) and find the switch plate connections identical assuming a triangle arranged switch contactor.

So I would say that is how it SHOULD be - well, your wiring diagram/switch contactor may differ.

Joe K

[ArtimusGordon]

Was helping a club member who had replaced his old wiring with new wiring. All worked well with the exception of the horn. The problem was with the length of the horn connector in the light switch. 1/8 in too short. (Not making contact with the horn rod) The problem was with the wire connector being soldered to the brass connector(with spring) not allowing the spring rod to fully extend. Solution was to melt the clip solder and push it 1/8 “ up the rod. Spring now makes contact and horn WORKS!

[Badpuppy]

Originally Posted by Mike Peters

Al: Maybe we are both wrong! The photo is from the Les Andrews "Troubleshooting and diagnostics", the 'blue book'. Les says the first light switch position to the right is bright lights, and second is dim lights. I didn't know that. I've always installed the headlight bulbs in the sockets to run dim first, and bright second to the right.
On your car, if what you have works for you, then leave it. Otherwise, you can change the wires around inside your headlights.

I have to say that Les is wrong here. Close examination of the wiring diagram shows that Cowl/Park is one position away from the Off position, Bright is two clicks away in the other direction.

[Mike Peters]

Badpuppy: Yup. You are correct and Les Is wrong here. I looked in a Model A Instruction Book, and yes, dim comes before bright to the right.

[PalAl]

Did ya all know you don't have to change the wiring around in the bucket..... just rotate the bulb 180 deg. in the socket. Many times you will see a bright light on the right and a dim on the left, pick one spin it 180 deg. and the problem is solved. I believe the bright filament is on the low side.... ah I think.

[garyj1930]

I have a problem with wiring. I just rewired my 30 Coupe with a new harness and I am having a problem when I turn on the headlights. Everything works but when I turn on the headlights the directional lights won't. When the lights are off they work fine. Any Ideas?

[Joe K]

Originally Posted by PalAl

Did ya all know you don't have to change the wiring around in the bucket..... just rotate the bulb 180 deg. in the socket. Many times you will see a bright light on the right and a dim on the left, pick one spin it 180 deg. and the problem is solved. I believe the bright filament is on the low side.... ah I think.

The bulbs are (or were) "omni-directional" meaning they could be turned 180 degrees.

And you have a condition where low beam is the filament on top - and high beam is the filament on the bottom - no matter how you place the bulb.

Today we have the improvement of 20-35 candlepower bulbs - these are no longer omnidirectional since you want to have the 35 candlepower side on the "bottom" (high beams)

(Think of the filaments being oriented as if in a mirror. Low beam filament is on top but reflects "down" - High beam filament is on the bottom but reflects "up.")

Add to this the problems with repop reflectors (ferrule turns or is not located correctly) and repop bulb sockets (indent on socket not made deep enough so can get turned in the ferrule as one adjusts the "focus" on the back of the headlight shell) and you have a system of "irregular results."

If your filaments are "side by each" then this has happened to you.

Joe K

[Joe K]

Originally Posted by garyj1930

I have a problem with wiring. I just rewired my 30 Coupe with a new harness and I am having a problem when I turn on the headlights. Everything works but when I turn on the headlights the directional lights won't. When the lights are off they work fine. Any Ideas?

When you say "directional" you mean the smaller, off-center bulb of a Twolight headlight?

These were originally "parking lights." And are not normally lit when the main bulbs are on.

Directional lights are usually done by an "add-on" kit. Or can use the cowl lights which are normally on a specialized wiring harness but can be adapted to be a directional.

Joe K