Electrical Dilema

DF Model A

DF Model A

Junior Member
To begin, I really,really dislike dealing with electrical issues. It's like a never ending game of whack-a-mole.
Here's my current issue: I have no brake or turn signal light on the left rear but I do have tail light. Right side works perfectly.
Next issue, when turning on the headlights, I get low beam on the right side and zip on the left. When I turn on high beam, I get high beam on the left and nothing on the right! Caveat, I just replaced the headlight bulbs with the LED focused beam bulb. Before replacing the bulbs, I assumed the left bulb had burned out since it was not working and looked discolored on the inside.
Any suggestions would be greatly appreciated before I start tearing out wiring. This is on my 1930 Roadster with original 6V positive ground. Thanks.
 
The tail-light sounds like a ground issue. Very common with restored/painted cars. The key here for diagnosis is BOTH bulbs don't work.

The head light sounds like an incorrect "synchronization" of the bakelite plate in your headlight switch enclosure - the 3 contact "feeler" is feeling out the wrong contacts.

Elsewhere there are directions for the proper assembly of the headlight switch. Particularly there is an "orientation" required of all the parts. You start with the switch in the OFF position. Next the spyder/spring, then bulb top/3 contacts. You want to be sure your switch/contacts are "centered to match the "off". Then you put the bakelite plate/wires in place. Orient the bakelite plate so the "non-contact" dimples align with the three contacts. Then you push everything together, make the 1/8th turn engaging the bulb cover and pushing the bail over everything to hold it to your steering column.

This is kind of the short version of how to do it. And I'm attempting to see this in my mind's eye. But the key in any assembly procedure is to find and use that "neutral" (off) spot both on the switch fingers (3) and the bakelite plate.

There are "keys" formed into the parts which will confirm your assembly as you go.

Joe K
p.s. confirm before you begin that you have a "3 contact" (later) Twolite switch, and not the "4 contact" Type H switch. This SHOULDN'T be your problem as you are at least a year beyond application of the early switch with your car. But stranger things have happened.
 
DF Model A said:
To begin, I really,really dislike dealing with electrical issues. It's like a never ending game of whack-a-mole.
Here's my current issue: I have no brake or turn signal light on the left rear but I do have tail light. Right side works perfectly.
Next issue, when turning on the headlights, I get low beam on the right side and zip on the left. When I turn on high beam, I get high beam on the left and nothing on the right! Caveat, I just replaced the headlight bulbs with the LED focused beam bulb. Before replacing the bulbs, I assumed the left bulb had burned out since it was not working and looked discolored on the inside.
Any suggestions would be greatly appreciated before I start tearing out wiring. This is on my 1930 Roadster with original 6V positive ground. Thanks.
Click to expand...
Take a wire and ground the taillight to a good ground see if it works? if not remove cover at bottom of column to check if not full of grease or bad connections
 
DF Model A said:
To begin, I really,really dislike dealing with electrical issues. It's like a never ending game of whack-a-mole.
Here's my current issue: I have no brake or turn signal light on the left rear but I do have tail light. Right side works perfectly.
Next issue, when turning on the headlights, I get low beam on the right side and zip on the left. When I turn on high beam, I get high beam on the left and nothing on the right! Caveat, I just replaced the headlight bulbs with the LED focused beam bulb. Before replacing the bulbs, I assumed the left bulb had burned out since it was not working and looked discolored on the inside.
Any suggestions would be greatly appreciated before I start tearing out wiring. This is on my 1930 Roadster with original 6V positive ground. Thanks.
Click to expand...

You must have a good ground path to the lights as they partially work ! Is the tail light bulb good ? Ohm the bulb , one lead to the bulb side one to the bulb contact, you should have continuity . If it good check for voltage on the bulb socket contact when someone pushs the brake pedal down . If you have to scratch the contact to get voltage you need to clean the contact , you can use a pencil and rub the contact with the eraser end until it’s shiny .

With the LED headlight bulbs don’t ohm them as you might damage them ! You have a good ground path as they light up partially , so you need to check for voltage on the bulb socket contacts , one contact for low beam , one contact is high beam . Again if the contacts are not shiny use the pencil eraser end and clean them . Easy Peezy game of operation !

A coworker worked on his inoperative headlights for a couple of hours until his wife asked him if the light bulbs were bad ?! He said they never burn out at the same time , she said they were installed at the same time ! New bulbs fix his headlights !!!
 
Electrons flow in a path. Any disruption in the path and they will not flow. They start at the battery, supplemented by generator, and return to the battery. Look for the any disruptions. The ground, mentioned above is one possible place. Burned out bulbs are another. Or bad switch contacts. Or bad bulb contacts, as mentioned above. Use your multimeter in voltage setting to trace the path from the battery back to the battery. Put on your detective hat. Look at electrical issues as a puzzle to solve.
 
the very first thing you do is get your test light. take the bulb out and see if there is power there. if you have power and the light does not come on then its either ground or bad bulb.

i don't know why we give complicated answers to a person with simple issues
 
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Thank you all for your sage advice. It really is heartening to know there is such a wealth of knowledge out there ready to help. I have tested all the bulb sockets with the volt meter and found good 6V readings on the headlight but not on the taillight so now I know where to begin with the taillight. I also discovered that the switch was misaligned (THANK YOU, JOE K!). Once the switch was in the correct position, I had light on both but the left was on high beam while the right was low. Not an electrical problem but an issue with the LED bulb that was fixed with the instructions that came with the bulbs. Now I just have to trace back from the tail light to find where the break might be.
 
Best way to describe Henry's Ford Model A lighting/switch setup.

"ITS NOT USER FRIENDLY."

The key is in knowing and working around the three (or four) "blank" positions on the bakelite plate. If you get it right you then see the "keying" which Henry intended as the starting point - but a starting point which is difficult to walk into blindly.

Better to see it through it's function than through it's configuration.

Thanks for the kudos. You're kind.

Joe K
 
DF Model A said:
Thank you all for your sage advice. It really is heartening to know there is such a wealth of knowledge out there ready to help. I have tested all the bulb sockets with the volt meter and found good 6V readings on the headlight but not on the taillight so now I know where to begin with the taillight. I also discovered that the switch was misaligned (THANK YOU, JOE K!). Once the switch was in the correct position, I had light on both but the left was on high beam while the right was low. Not an electrical problem but an issue with the LED bulb that was fixed with the instructions that came with the bulbs. Now I just have to trace back from the tail light to find where the break might be.
Click to expand...


the easiest solution to the high/low headlight may have been to switch the bulb but, if it was installed properly, it's possible that the wires in the socket were switched. Again, not a difficult fix, but something to keep in mind.
 
One thing I discovered in my Model A formative days was to scrape all fresh paint from the light bar receptacles for the headlight shells. It's easy to get too aggressive when spray painting small items like this and over-coat them. If the area where the naughty bulbous part of the headlight shell nestles into is coated with paint, there will be a bad ground. This will result in headlights burning dimly, if at all. I have fixed a number of lighting issues like this simply by scraping this area down to bare metal so that the headlight makes good contact with the headlight bar.
By extension, the same is true with taillights, as has been stated. I won't dog pile more on what's been advised so far other than post a warning to others experiencing taillight problems. There are a ton of fiberglass fenders out there and unless special care is taken to ground the taillight bracket, the taillight will either not work at all or will be dim. I usually run an extra wire from the mounting bracket to the rear fender bracket to establish a ground. This caveat may not apply to the OP and his Model A, but others out there in Readerland may run into a case of fiberglassitis in a future Model A. Who thinks fiberglass when viewing a nicely painted black Model A fender??? Heck, even I outfitted a 1928 Coupe with all new fiberglass fenders in the early 1970's because they were so cheap compared to steel fenders. It took this genius a while to figure out why I was having trouble getting the lights to work. I wish someone had told me back then about the relationship between fiberglass and electrical grounding! Duh on me!!!
Marshall
 
I have noted abandoning Ford "Bullet ends" and instead going with modern crimp style electrical connectors just inside the headlight shell.

This leaves room in the connecting conduit for ANOTHER wire which serves as a ground when brought back to somewhere adjacent to the engine. (Besides overcoming probably permanently Ford's ill conceived bullet/filler/receptacle design for connecting lights)

The conduit still connects to the base of the headlight shell normally. You can't tell it's been "modified."

Joe K
 
Joe K, this is exactly what I discovered when I located the "bullet" connector under the rear fender and attached to the frame. When I attempted to disconnect the bullet connector it literally disintegrated in my fingers. I used a heat shrink solder seal connector left over from an antique mahogany boat restoration to reconnect the wires and that solved the issue and will likely last many more years. Problem solved and tail/stop/turn signal works perfectly. My next project will be to locate all the exposed to the weather "bullet" connectors and replace them with the same heat shrink solder connectors. Maybe overkill but at least I know the connections will not fail. To be fair, the bullet connectors did manage to last for many more years that Henry ever expected his cars to last.
 
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