I set the Model A on fire.................AGAIN.

Skeezixx

Skeezixx

Senior Member
While parked idling in front of a friends shop demonstrating how smoothly it idled with the new Zenith 13922 carb installed just minutes before, he noticed the car filling up with smoke.
It was coming out profusely from behind the instrument panel. I quickly undid the screws and found the ammeter on fire.

I deduced that the generator cut out was at fault and removed it. I drove it home on the battery.

This is the third electrical fire I have had since getting the car in July. Once the battery cable chafed against the frame at an intersection and the cotton insulation ignited into flames, and a week ago I had a headlight socket short out and the wires melt at a redlight.

This combined with the shimmy I can't seem to eliminate enables me to provide quite a spectacle for the neighbors.

For a quick fix this week's parts order included a new cutout and ammeter but ultimately (after addressing some of the other problems) I intend to install an alternator with a voltage regulator and fuse block.

Due to the incendiary nature of the Model A Ford I recommend carrying fire extinguishers at all times.
 
A (working) fire extinguisher is a good idea for any car, especially a vintage car.

Hopefully you will never need to use it...

Hang in there...

SC Frank
 
Skeezixx said:
While parked idling in front of a friends shop demonstrating how smoothly it idled with the new Zenith 13922 carb installed just minutes before, he noticed the car filling up with smoke.
It was coming out profusely from behind the instrument panel. I quickly undid the screws and found the ammeter on fire.

I deduced that the generator cut out was at fault and removed it. I drove it home on the battery.
Click to expand...
If the fire was in the ammeter, how did you come to the conclusion the generator cutout was at fault?

Was it an original ammeter, or a reproduction?
 
A fuse block is always a good thing to have. It will let you know right away that there is a short somewhere. I would have installed one after the first fire.
 
i recomend a chevy 3 wire alt, easy to wire and you eliminate the reg, that is the way to go if your using 12v
 
Before you condemn everything and change to modern or repop parts, try restoring originals properly. Original light sockets are 10X better than repops, properly rebuilt ammeters are better than any of the repops, and alternators can go wild and burn up too. If your wiring harness is frayed, abraded or corroded, you can replace that part with a complete new harness.
 
In the interest of keeping the car nice, and not having to call the insurance company, I installed a fire extinguisher in each car, and devised a switch and fuse setup that I mount on the inside of the firewall, on the terminal box screws. I sent in an article to the model "A news last year. It was printed very small, so it was hard to see, but you can get the idea.
 
Sounds like time for a new wiring harness and a fuse assembly.

It also speaks pretty well for the original design of the Model A Ford that you could set it on fire three times and still have a drivable car.
 
Blessyouboys said:
If the fire was in the ammeter, how did you come to the conclusion the generator cutout was at fault?

Was it an original ammeter, or a reproduction?
Click to expand...

I suspect it was an original because it looked old and tired.

I figured it was the cutout because that would (I think) allow the generator to overcharge the system and the first link in that scenario would be the monitoring device.

If I am wrong somebody please clue me in.

BTW. There is some kind of chemical or something in the ammeter that really stinks and leaves a greasy film when it catches on fire.
 

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2manycars said:
In the interest of keeping the car nice, and not having to call the insurance company, I installed a fire extinguisher in each car, and devised a switch and fuse setup that I mount on the inside of the firewall, on the terminal box screws. I sent in an article to the model "A news last year. It was printed very small, so it was hard to see, but you can get the idea.
Click to expand...

2many.. do you have a copy of the article and a pic?

That unobtrusive switch and fuse rig sounds interesting.
 
A loose wire on the ammeter could cause the generator to increase its output and allow the ammeter wiring connection to heat up. You really need to check all wiring connections to make sure they are clean and tight. A little prevention might help avoid fire number 4. If you have had three fires, I still think you should consider a replacement harness and a fuse assembly. Good Luck.... and don't forget to keep a fire extinguisher in the car.
 
Put a fuse holder and fuse where your battery cable mounts on your starter Get one of those plastic ties and put it around the glass part of the fuse so when something like a this happens one can just reach down and yank the fuse out. I have mine set up that way so every time I leave my sit for some time I just open the hood and pull the fuse. I use a red tie so I find it after I put it down and forget where it is Oops!;)
 
Skeezixx said:
I suspect it was an original because it looked old and tired.
From what little I see, it appears original.

I figured it was the cutout because that would (I think) allow the generator to overcharge the system and the first link in that scenario would be the monitoring device.The cutout only functions to disconnect the generator from the battery when not running at speed, so the battery doesn't discharge through it. It has nothing to do with regulation, that is from the 3rd brush setting. A bad cutout will not cause excessive output.

If I am wrong somebody please clue me in.

BTW. There is some kind of chemical or something in the ammeter that really stinks and leaves a greasy film when it catches on fire.
Click to expand...
Likely from the oiled or phenolic (soybean!) impregnated insulator card stock behind the internal shunt, which overheated and burned up. You probably had another short to ground downstream of the ammeter.
 
Skeezixx said:
2many.. do you have a copy of the article and a pic?

That unobtrusive switch and fuse rig sounds interesting.
Click to expand...

Send me a private message, with your email address, and I will send you the artlcle and all the photos, (in color, not b&w as printed in the News).
 
Sounds like you have a "hot" car! :) LOL

I agree with MikeK and MCHinson. Find the source of the problem and don't start throwing repro parts at it. I ONLY recommend 80 year old original cutouts, but there are some repro cutouts that will work OK also. The main thing is to make sure every electrical connection is clean and tight. Make sure a repro switch doesn't have terminals that hit the gas tank, and make sure the ammeter terminals are clean and tight (both inside and outside tha meter). Many people like to solder the studs to the buss bar inside the meter for a sure connection. After working on the inside of the meter, anything that can be seen through the needle slot should be painted flat black.

Take care of the switch and meter and that's about all that can go bad behind the instrument panel. Also make sure the terminal box connections are clean and tight. I see a lot of them that are loose and corroded.
 
MikeK said:
I figured it was the cutout because that would (I think) allow the generator to overcharge the system and the first link in that scenario would be the monitoring device.The cutout only functions to disconnect the generator from the battery when not running at speed, so the battery doesn't discharge through it. It has nothing to do with regulation, that is from the 3rd brush setting. A bad cutout will not cause excessive output.
Click to expand...

After the fire was out the generator was so hot I couldn't touch it.

What exactly is going on with my charging system?
 
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