Night cruise-no lights

bobpo

bobpo

Well-known member
My wife and I took a great Sunday afternoon drive in the coupe. As it began to get late I figured we'd cruise home with the lights on. No Problem, as the young'ns say these days. :cool:

As it started getting dark, I turned the Headlights on and the Ammeter needle disappeared to the left side of the gauge. :eek: I tapped the gauge, but this time, nothing happened. Then I noticed that I had no Horn either.

I parked alongside backroad, got out and noticed that the left headlight was very, very dim and there was no right headlight at all. We were about 8 miles from home and NO HEADLIGHTS. Fortunatley out here in the (flatland country) there are a lot of backroads, so I picked the one with the least traffic. Two oncoming cars in 8 miles. I had used the headlights before with no problems.

Back in the shop I noticed that the fan belt was somewhat loose. I might add that I'm running an Alternator. New a year or so ago. Checked the light bulbs, all are fine. 32/50's. I charged the battery just to be safe and I tightened the belt. Headlights still bury the Ammeter.

It ran fine with just the parking lights only. Even the Ammeter Gauge was O.K. with just the parking lights on.

I am horrible with automotive electricity, and I know that doesn't help, but sure would like to figure this out. :p

Any ideas out there in the Fordbarn College?
 
Alternators will solve all you electrical problems, or cause some.

Sounds like your not charging at all. Unplug your battery and see if it will run.

No fix here as I know nothing about alternators, and am just learning about generators.

Good luck!

**************
it's not the alternator. Both lights should turn on, and your lights should only draw 10-15 amps if they are 50w bulbs. You have a short somewhere in your headlights. May be it's the grounds, the sockets, or the wires. But the alternator would not cause this problem.

Geez.... Yep I'm an idiot, I went straight for the alternator not supplying enough power. Short was obvious.
 
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Thanks Tinker,

You might be on to something here. I kept the Old Generator. There was nothing wrong with it. Maybe I should just put it back on. I'll wait til I get some more feedback.....
 
Since you mention "No right headlight" at the same time as the severe discharge, start by checking for a short to, or within that light. The vibration of an A can eat through insulation in a hurry anywhere it touches anything.

Check where wiring exits the column switch, where it is clipped to the frame, next to the radiator, through the flex conduit, in the lousy connector plug at the base of the lamp housings, too. When you think you've found it you can test it as follows:
With one battery lead disconnected (engine stopped) remove BOTH headlight bulbs, turn the steering wheel light switch ON. A continuity tester or an ohm meter should show no continuity (infinity ohms) between the center bulb socket pin and the shell (ground).
 
Hello there! Im still working on my first model A now and was scanning the forum just to learn a thing or two about what I may run across in the future. Im by far not an automotive electrical tech but I have been a Master electrician for a decade and although automotive electrical and building electrical are two different things I feel the theories are simular enough. Also I have a 27 Model T touring car that Ive had the pleasure or having to rewire.
Always start with the most simple things first and as suggested before checking to see whether your alternator is good would be my first thing on the check list. if you remove the positive lead and she stays running then she's working but still yet if enough load is applied she might have a fault. The proper way to test would be to take it to the auto parts store for a more accurate test.
Still yet if you remove the positive lead and it still runs keep checking. This may sound too obvious but remarkably it happened to me so... check the bulbs. Should the headlights possibly be wired in series with each other and one goes out it would cause the problem. If they arnt in series with each other then one should still burn bright. So the next thing and from my experiance, the most accurate, would be a frayed wire. Possibly the negitive wire going to the lights. I say this because one light is burning dim. Electricity has to have a circuit to run. The word circuit comes from the word circle. Electricity is always trying to get to the ground and so we interupt it with resistance along the way. Resistance is a light bulb. If you have power going to the bulb yet some where along the path to ground it is cut short electricity wont pass that way because it will always take the fastest route.
Anyway to make it simple check your alternator, bulbs and wiring. If all of that seems fine then take a look at your switch. Ive been down that road with the ole T. Wiggle each connection with the light switch on.
I know Ive been very windy here but just trying to help.
If all else fails get a 2 million watt candle power light put the wife on the running board and tell her to hold on tight,
 
Hello there! Im still working on my first model A now and was scanning the forum just to learn a thing or two about what I may run across in the future. Im by far not an automotive electrical tech but I have been a Master electrician for a decade and although automotive electrical and building electrical are two different things I feel the theories are simular enough. Also I have a 27 Model T touring car that Ive had the pleasure or having to rewire.
Always start with the most simple things first and as suggested before checking to see whether your alternator is good would be my first thing on the check list. if you remove the positive lead and she stays running then she's working but still yet if enough load is applied she might have a fault. The proper way to test would be to take it to the auto parts store for a more accurate test.
Still yet if you remove the positive lead and it still runs keep checking. This may sound too obvious but remarkably it happened to me so... check the bulbs. Should the headlights possibly be wired in series with each other and one goes out it would cause the problem. If they arnt in series with each other then one should still burn bright. So the next thing and from my experiance, the most accurate, would be a frayed wire. Possibly the negitive wire going to the lights. I say this because one light is burning dim. Electricity has to have a circuit to run. The word circuit comes from the word circle. Electricity is always trying to get to the ground and so we interupt it with resistance along the way. Resistance is a light bulb. If you have power going to the bulb yet some where along the path to ground it is cut short electricity wont pass that way because it will always take the fastest route.
Anyway to make it simple check your alternator, bulbs and wiring. If all of that seems fine then take a look at your switch. Ive been down that road with the ole T. Wiggle each connection with the light switch on.
I know Ive been very windy here but just trying to help.
If all else fails get a 2 million watt candle power light put the wife on the running board and tell her to hold on tight,
 
My first check would be the socket at the base of the right headlight. It sounds like the terminal (s) are shorted to ground.
 
As usual Tom is on the right track, maybe more to that locomotive than a personal liking.

Is the electrical system 6 or 12 volt? Positive or negative ground? On a stock system the headlights get the voltage from the generator cutout. Are your lights wired to the alternator?

Like Tom said, disconnect the right headlight at the socket and turn the lights on to check the amperage draw. If it still buries the needle then disconnect the left headlight. If the guage reacts properly, slight discharge, then reconnect the right headlight and check the amperage draw. See the method to the madness? Isolation of the problem. When you get through this let me know if the problem was isolated and fixed or if it still persists.
 
bobpo said:
Thanks Tinker,

You might be on to something here. I kept the Old Generator. There was nothing wrong with it. Maybe I should just put it back on. I'll wait til I get some more feedback.....
Click to expand...

it's not the alternator. Both lights should turn on, and your lights should only draw 10-15 amps if they are 50w bulbs. You have a short somewhere in your headlights. May be it's the grounds, the sockets, or the wires. But the alternator would not cause this problem.
 
You stated that the cowl lights worked, so it's got to be in the wires leading to the headlights or inwithin the headlight shells. Does the horn work? JMO
Paul in CT
 
Tom,

You know what? I got to thinking (rare) when I read your post. I JUST INSTALLED THE FOCUS SCREWS FOR THE FIRST TIME SINCE THE RESTORATION. I think I may have turned the screw in too far. THAT WOULD SHORT IT....RIGHT..?????////???

P.S. I am saving all these responses.

Thanks from a NEWBIE (even tho it says I'm a Senior....LOL and the Horn is weak, Now that is.....
 
In my experience, this problem occurs regularly with repop sockets, as Tom suggests. OTOH, screwing in the focus screw until it cuts into the wiring will do it too. If any problem arises "shortly" ( heh heh) after recent work, always inspect the work.
 
bobpo said:
Tom,

You know what? I got to thinking (rare) when I read your post. I JUST INSTALLED THE FOCUS SCREWS FOR THE FIRST TIME SINCE THE RESTORATION. I think I may have turned the screw in too far. THAT WOULD SHORT IT....RIGHT..?????////???

P.S. I am saving all these responses.

Thanks from a NEWBIE (even tho it says I'm a Senior....LOL and the Horn is weak, Now that is.....
Click to expand...

I think you found your problem. I've seen the same thing happen to horn brush holders when using a repro cover screw, and someone screws it in so far that they deform the brush holder, besides shorting the horn.
 
Well, I pulled the right headlight and found that the insulation had been worn thru to the wire and it shorted. Sure Nuff.....

Problem now is that I completely disconnected that headlight and re-installed the lens and now have no lights at all, and I insulated the wires so they wouldn't touch.

I had tail lights before.....???????
 
Jeff, I think you have a great idea pertaining to the inline fuse, I will order one this coming week along with new headlight sockets, etc.. Already got a new spare belt for the alternator. I learned that this belt has to be tight.
 
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