Headlight/tail light problems

Barber31

Barber31

Well-known member
I'm not getting any lights working front or back and I'm thinking it may be a ground issue due to the powder coated frame and freshly painted fenders and parts. So what's a good way to isolate the ground issue? I have power at the wires coming out the light switch housing and I'm grounding the headlamps from the mounting bolt to the block but still no lights. Any ideas?
 
Try grounding the headlamp shell by touching the jumper wire to it. The mounting bolt and nut may need to be cleaned up.
 
Since it seems you may have powder coated the light brackets, front and rear, it may be that you need to remove the coating in the areas where the grounding would be taking place. If you don't do that, I would advise running another wire from the lights to frame and checking the lights then.
This ground also includes checking to be sure the frame and battery have a good connection also.
 
To ensure a good ground on tail lights (and other electrical things that need a ground), I use "internal tooth lock washers" (available at Home Depot). Once tightened up, they look like regular washers. But their sharp little teeth cut through any paint or rust (or powder coat) and connect with the metal for a good connection.
 
The frame and light brackets are both powder coated. I got the battery grounded to the frame good but I think the lamps still are not. I'm trying to tackle the headlamps first and work my way to the back but not making any progress.
Question 1 - The light switch gets power directly from the gen and disperses power from there to the lights?
The yellow/blue wire that is plugged in the center of the light switch shows power on my multimeter. When I'm touching my multimeter test lead from ground to the headlamp wires, I get power from the red, green and yellow lamp wires. So it seems the front lamps are getting power so when I try to ground them with a seperate test lead nothing happens. That's where I'm confused.
 
I'll try that Tom. The bolts and nut are clean but I'll connect to the shell.

Dawizard, I'm trying to skip that part for now and ground directly at the lamp to verify its grounding problems but the fact that that's not even working has got me stumped. Also everything worked when it was a rust bucket before I restored the vehicle. Haha.

Jim, I'll look into those. Thanks.
 
Ok, providing you have the stock wire colors, the center wire is power from the Horn. and Blue/Yellow.
The Yellow is power for the lights from the generator to the light switch.
If you have juice at the headlight shell on the Black/Green and Black/Red with the switch turned left and right, you now need to open the headlight and make sure that when the plug is inserted into the socket, the two wires are indeed contacting the two light bulb wires on the inside. Either one or the other plugs could be twisted or shifted to lose contact.
If you have power there and then check the plug with the bulb out and still have power, the bulb itself may be bad, or you still do not have sufficient ground to the headlight bell.
 
The power I'm getting when poking the wires with multimeter is not affected when I switch the light lever to park or low or high. Maybe I'm not testing it right? I have one test lead poked thru the original colored wires and the other to ground. Is that sufficient for testing? It's shows power but like I said nothing changes when I move the lever. One of my bulbs is popped but not my park lamps and that's what I'm trying to get lit. Once I get one I know I can get the others.
 
Connect a volt meter between the headlamp socket ground (or shell) and a good engine ground. If you get any reading, then the headlamps need a better ground.
 
Damn, tis a shame you are in Tx., I would make a house call.

This sounds like there is something wrong with the switch, but not being there with it in my hand and seeing what you do it is really hard to narrow it down to one specific thing.

So, lets start with the basics and work from there.

Remove the 2 wires from the Cut-Out and place a screw and nut through the holes tightly and place a bit of tape around the connection to keep it from shorting out.
BE CAREFUL, these wires will be LIVE!!
Now, remove the bulb from the bottom of the steering column and open it up.
Take your "ground jumper" and touch it to the Center terminal, the Horn should honk.
Be careful to NOT touch that jumper to any other terminal on the switch.
Next, there is a Yellow wire, THIS IS BATTERY, take one end of the jumper and clip it onto the Yellow wire. That circuit has only 2 wires on it, a Yellow and a Green wire.
Take the other end and of your jumper and touch it to the Black, which should light up the Cowl and Tail lights and Park.
Touching the jumper to the Black/Red should light up the Bright headlight, touching the Black/Green should light up the Low headlight.

Now, make sure you have good grounds on all the lights to be lit, if this works, there is something off in the switch, if not, we will work from there.

This is the beginning of the troubleshooting, if you skip this part, you will need to do it sometime unless you find another problem.
 
Tom - I'll try that. It's a whole lot simpler than Dawizards method!

Dawizard - If you decide to make that house call I'll treat you to some good Tex-Mex tacos!! Haha. I guess I got my thanksgiving project waiting for me. I'll report back what I find. Thanks again. It's much appreciated.
 
Morning. I woke up early to work on this and I got some info. First was the horn test. My horn normally blows strong but when I did the test I could hear a click in the horn but nothing else. I hooked it back up that way it was before the test now the horn doesn't blow! The second test was successful. The rear lamps lit up. The third test was not. No headlamp bulb lit up. I even had a ground jumper on the shell to help with grounding. I'm gonna replace the bulbs and clean all the contacts in the switch. Might take a while because I don't think I can get these bulbs locally. Maybe the park bulb but I'm not sure about the low/bright bulb. As far as the horn goes, is there something inside the horn that could have burned up?
 
One screw to remove the horn cover, then you can put a coupe drops of oil on the shaft felts. The other screw on the rear of the horn is to adjust the shaft pressure against the horn diaphram. One click can make the horn spin, or not spin. Your's may need to be turned CCW one or two clicks.
 
Barber, did you disconnect the wires off the Cut-out before starting all this this morning?

If not, you may have a generator trying to be a motor and screwing up all the works. What I was trying to do with my last posting was eliminate some of the other possibilities.

If your horn was working when you started before the restoration, it isn't broke, the problem is somewhere else.

Troubleshooting is a step by step process, if you skip a step it screws up the whole process.

Now, tell me, what is the voltage on the Yellow wire on the light switch? But first, remove and screw together the 2 wires off the Cut-out.

J.C.
 
Yes. I did remove those cut out wires. When I get home after work I'll test the volts. I'll also post some pics. Maybe that will help give a visual.
 
Hey Barber, sorry I sounded kinda short on the last post. It is possible that while you were testing you may have taken the top charge off the battery. While you are doing all this testing, it may help things out to place the charger on the battery and at least bring it up to full while this is ongoing.

One thing also to think about is, when you replace the wires on the Cut-out, be sure to take a jumper and short across the in and out terminals of the Cut-out, this will ensure the generator is properly polarized.

J.C. ....still thinking about your electrical problems.
 
For anyone searching for a "GOOD" electrical ground:

1. First: From past experiences, it appears that about ninety-nine percent (99%) of causes as to why Model A headlights and tail lights do not work and function properly is because of a poor, or absolutely no clean metal to clean metal ground.

2. Second: Why continue to waste valuable time cutting & stripping sections of electrical wires, attaching wire connectors, and running connecting ground wires to "NO" ground?

3. Third: Pay attention to Mr. Tom W's reply no. 9, which is the quick & proper way to find a good ground when all parts of metal is covered with paint, rust, rat fur or whatever ........ i.e., use a volt meter to "verify" and establish a "definite" and clean, "unpainted" metal location for connecting to a good ground on both ends of each ground wire.

4. Volt meters are like George Washington and not at all like our doubtful unreliable journalist's who make false predictions in the NY Times ..... if a volt meter tells you found a good ground on both ends of your ground wire ..... volt meters like old George, never told a lie ..... or something like that. LOL

Hope this helps to "very quickly" light up your Model A lights once and for all.
 
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Ya know, I just had a brain fart and stunk up the whole room.

Let's take this one step back and check where the yellow wire is hooked to the cable atop the Starter Switch, First be sure there is no crud around this connection, and be sure it is tight.

This could be a starting point for voltage loss if the connection isn't clean and tight.

J.C.
 
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