12 Volts Are Welding My Starter Button!

R

rmak

Senior Member
The previous owner converted my A Model to 12 volts. That sounded good to me until yesterday. I hooked up the battery by slipping on the battery cables so I could turn the engine over so I could get close to top dead center before I used the crank.
I was tapping the starter about four times and suddenly it stuck on. I popped off the cable and tapped the starter with a rubber hammer thinking something internally was wrong. Everything was OK when I re-installed the cable. Darned if it happened again. This time I couldn't re-install the cable because the starter was still on and the battery would spark.
I rubber hammered and all was fine until...yep, stuck again. I forgot to mention that I played with the starter rod to make sure nothing was binding.
Finally I took the starter switch off and found a small spot that looked like a weld spot. I'm beginning to wonder if the increased voltage is welding the copper together. If it is, what's the fix? This can't be the first 12V conversion.
Anyhow, thanks again. This site is becoming a lifesaver for me.:D

Oh yeah. The pin worked into the hole just like Mr. Ford said it would.
 
Sorry for the double post, but I did search and found info on sanding the surfaces. I will try that, but I'd still like to hear about what people think.
 
What I did with mine was too force the blade down perminently, and use a soleniod switch.You will need to change your igition switch to one with a start position.
 
I think I would switch back to 6 volts.

It's easy to switch back to 6 volts. I sure like the way the starter sounds right and works great with the correct voltage.
 
This is one of the reasons you should convert your stater to 12V.
Easy to do just rewire your field coils in series, BUT you need a second set of field coils to do the job or buy 12V coils from the part suppliers.
herb
Concord CA
 
Sounds more like a junk switch to me. Most repros aren't worth a damn. Why go adding a bunch of extra s*** to fix a very easy problem?

I don't think 12V would weld your switch to the starter post, if that was the case you'd have alot of cars with 'welded' switches. Over time a wear pattern develops at the point the two pieces make contact. This holds true for 6V, 12V whatever. A similar example is the points in your distributor.

Like Tom said, you're better off with 6V. Unless you plan to run Modern A/C and radio etc there's no need for 12V. 12V is more forgiving of bad grounds and so forth hence why people 'upgrade' the car with 12V.
 
This is a replacement starter switch. It looks pretty chincy, Does anyone make a good one? I would be glad to pay for a good switch rather than re-do everything. Thanks
 
I don't know who reproduces a good one anymore. I had a repro starter switch on one of the cars and the copper strap broke in two the third time I hit the button. :mad:

Bought a few of the older NORS starter switches at shows & have had zero trouble since then. Still using the same one I put on in 1993.

Bert's in Denver, CO probably has a few good originals.
 
{QUOTE} I don't think 12V would weld your switch to the starter post, if that was the case you'd have alot of cars with 'welded' switches. Over time a wear pattern develops at the point the two pieces make contact. This holds true for 6V, 12V whatever. A similar example is the points in your distributor.

Usually, the output of the coil has a resistor in the line, or in the coil, to drop the voltage down to 6/8volts, because non of the points/condensers are made for 12 volts.
 
The starter could be drawing too much current. This could be caused by warn bushings alowing the armature to drag on the pole pieces. Another possibility could be brush holders draging the armature, this would be the result of extreamly warn brushes. Check your starter over and make sure that it is operating properly. I also like Tom's idea, convert back to 6 volts
 
Its not the volts, its the amps (current flow) that is "welding" the contact. Normally 12 v will only use half the current of 6v unless your starter is still wired for 6v, in which case it still draws the heavy current and turns twice as fast. Could be the starter parts are old or worn and drawing too much current as noted by walt. I think that the quick "tapping" which creates a fast make/break with heavy sparking and heating may be a problem as well.
 
just take a piece of sand paper, and sand down the "high" spots on the copper button on the starter and the copper strip on the switch. These are just high spots which made contact first, causing the electricity to surge through this point first, causing them to melt together. I had this happen to mine, and sanded it down even 3 years ago, and I've never had a problem since.
 
Jordan said:
just take a piece of sand paper, and sand down the "high" spots on the copper button on the starter and the copper strip on the switch. These are just high spots which made contact first, causing the electricity to surge through this point first, causing them to melt together. I had this happen to mine, and sanded it down even 3 years ago, and I've never had a problem since.
Click to expand...
I'm hoping that this takes care of mine. It had a repro switch on it when I bought the car, it was scrap after welding itslef. I had to take quite a bit off the copper button, but it did clean up fairly nice. I'll be starting it up this next week sometime.
 
I had the same problem with a six volt starter. Then when I replaced it with a
new switch made by Vintique, I had the same problem when it was brand new.
Another switch solved the problem. I don't think the 12 volts is the problem, but
I highly suggest staying away from the Vintique brand, JMHO.

Jack
 
PC/SR is right, its the amperage. Your trouble is most likely the switch. Often the movable contact in the switch is not centered and binds on the side of the switch housing, an easily remedied situation.
 
p.s. The A starter will run cooler on 12v than on 6, plus the engine will start more quickly and you can easily use modern gadgets.
 
had it happen to me at 6 vts i just cleen the terminals and put electro greese on them, this greese will prevent hot arching its what its designed for.
 
Sorry to resurrect this thread, but I wanted to share what I found out today. I took off the starter switch and did the sanding and greasing with dielectric, made sure the nut was tight so the copper wouldn't move when I put the wires on the post, etc. When it was all installed I noticed that the rod was not running true to the switch and it was skewed in the direction so where the spots were welding would contact first. I bent the rod ever so slightly so it would push directly down and not push off to the side. 15 trial starts and no sticking or welding yet! Hope that fixed her up.;)
 
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