The Stovebolt Site Forums The Shop Area The Electrical Bay AD ignition switch

Think I may have fried it leaving it on for a while today whilst working on the truck. Getting intermittent voltage at the coil/ ballast resistor. Had some other obligations and couldn’t fully diagnose.

Assuming that’s the issue, where would I get a switch? Parts stores don’t seem to list one.

This is a 12v conversion from the distant past. For all I know it could be the original switch. I can tell the tumbler has a lot of miles on it, anyway.

Had a long drive and then a HS football game to ponder my hurried diagnosis. I have a no crank situation. Ignition switch shouldn’t have anything to do with that.

How would I go about differentiating starter vs just the stomp switch?

Hard to do electrically with the stomp switch in place.

Turn on the headlights. Nice and bright? Now stomp the starter. Did the headlights go dim/out? If so, the battery or battery cables are likely at fault. Make sure both ends of both cables are clean and tight.

With wear, I've seen stomp switches that needed to be pushed just a bit more to make contact. Find something that you can put over the top of the switch (Shiner Bock twist off cap comes to mind) and stomp again. If that makes it crank you could either find something more permanent, check for loose stomp linkage or replace the switch.

I've never tried it, but you should be able to ...
make sure the transmission is in neutral
remove the battery cable from the start switch
remove the start switch
manually engage the starter drive (Bendix)
touch the battery cable to the stud that the starter switch contacts

If the starter cranks replace the stomp switch (or maybe just clean up the contacts).
Have the battery tested.

I have 12v on both side of the ballast resistor with key on and points closed. Could that have anything to do with the starter switch? Or just a sign that I fried it along with whatever else?

Ignition switch on and points closed GM says you should have around 5 to 7 volts on the bottom side of the ballast resistor. If you have more than 7, here is a list of what to check:
Contacts not closed
loose connection in distributor
distributor not grounded to engine
faulty contacts
loose connection between coil and distributor
resistor out of circuit due to shorted or incorrect wiring
starting contacts of ignition switch stay closed
resistor has too little resistance...should be 1.4 to 1.65 ohms
coil primary is open.

Unfortunately there is no check list for a stomp starter on a vehicle with 12v, but any of the GM shop manuals (say for 1957 and newer) will give lots of info for 12v.

I assume the points really are closed and clean and the starter switch is a "12 volt" aftermarket model with a small wire connected to the bypass stud on the side. If so, remove the wire and do your "key on and points closed" test again.

If that gets the coil side of the ballast resistor down to around 9 volts the stomp switch is bad. But that shouldn't keep the engine from running. It would just burn up a set of points faster.

If the coil side of the ballast resistor is still 12 volts either ...
a. the points aren't really closed
b. the wire from the ballast resistor to coil+ is bad
c. somehow the plate the points are mounted on is not grounded

To test that...
a. leave the negative meter lead on ground, the ignition switch on and the points closed
b. remove the distributor cap
c. touch the positive meter lead to coil +
d. if zero volts, fix the wire between coil + and try the whole test again
e. touch the positive meter lead to coil -
f. if zero volts, replace the coil and try the whole test again
g. touch the positive meter lead to the stud on the side of the distributor where the coil - wire attaches
h. if zero volts, replace the coil - to distributor side stud and try the whole test again
i. touch the positive meter lead to point spring where it attaches to the distributor side stud
j. if zero volts, replace the stud and try the whole test again
k. touch the positive meter lead to the plate the points mount on
l. if 12 volts, the distributor is not grounded. If zero volts, OK. Let's worry about this later.

You type (and probably think) faster than I do Jon.

I don't know about the thinking part, Bill...

ASSUMING you know what "I have a no crank situation." means instead of "no start situation". No crank means the starter will not operate. If that is the case, put away your meter. The ballast resistor, the points, the coil, ignition switch....have nothing to do with your issue.

The stomp stater has two operations, a mechanical and an electrical. As you know the mechanical levers slide the starter pinion into contact with the flywheel. As that happens, a button switch/stomp switch on top of the starter is pushed which pushes a big contact down onto a big starter contact that is part of the starter.

You have to get the starter to spin, not worry about voltage at a bunch of places.
So....Check..
1. The battery for 12.6V or jump it.
2. Battery posts shinny clean.
3. Pos and neg battery cables and their clamps.
4. Pos and neg battery cable ends. Ground neg end and starter pos end.
5. The cables themselves, no fraying or coorosion of loos or breakage,

I'm assuming you don't have any noise from starter at all. If you have a no crank and you check all above. Report what you find and I will advise a test or two.

How would I go about differentiating starter vs just the stomp switch? Good question.


1. Disconnect negative battery cable at battery.
2. Examine foot linkage operation. Does it slide pinion into flywheel gear? Does it seem to depress button fully?
3. Disconnect stomp linkage by removing cotter pin and pivot pin.
4. Remove pos batt cable from stomp switch and remove stomp switch, examine it's copper contact and it's push button operation.
5. You will see the starter copper lug on top of starter. Could be worn down or pitted. They are available. If the stomp switch or that lug seem other than in good condition, replace.


If you want to test, be sure battery is up. Key OFF.
Remove center distributor tower wire. Put in neutral, block tires, be sure truck won't move.......or start.
BE CAREFUL not to touch positive cable that is still loose from stomp switch to anything. Install neg battery cable. Now touch that pos batt cable to the copper lug on top of starter to see if starter spins. A one or two second touch. Lever will still be disconnected and pinion should not engage starter, but who knows. If it does you have in neutral, etc.
If starter spins nice, replace lug and stomp switch. No spin..... bad starter.....bad ground cable/connection.

EDIT..........pinion should not engage starter flywheel

Thanks all, for the support and info. I need to work back through some of this stuff to understand what happened and why.

There’s a bigger backstory I will post in another thread on a different subforum. The “no crank” (that’s truly what it was - nothing) symptom late Friday evening came in the last hour of preparation to take the truck on a planned long drive event.

I awoke in the wee hours of the morning on Saturday, with a spare starter in hand ready to swap the switch and/or the whole thing as a Hail Mary attempt to make the trip happen. After some fiddling with the battery cable connections, JW fired right off. I don’t understand - I had done plenty of fiddling with the battery connections the evening prior.

Anywoo - truck ran pretty flawlessly yesterday over 380ish miles to the event and back. One little hiccup that may or may not be related to all this. I’ll type details on that later.

Good to hear you got it fixed. Sometimes it really is the simplest things.