Strange Electrical Problem

[jimvette59]

Wow did you check the starter switch on top of the starter? That could be the culprit. I would take that apart first or by pass it and see if the starter works. JMO

[Rob Doe]

Originally Posted by Dave in MN

Guys, Please help me out here as I have not rebuilt a Model A starter motor in all the years I have worked on Model A's....
Is it possible he has a bad spot on the commutator of the armature resulting in no action or draw when the starter switch is closed? Could this situation along with open points be the exact description he is conveying?
Thanks for any comments.
Good Day!

X2 Dave, I've had a 94 Chevy pickup do that one. Tapped on the starter with a light hammer while another repeatedly attempted to start it. 3rd or 4th attempt she started. It never did it again. Also had electric window motors do it too. Clean the commutator and check brushes???


As for the primary ignition circuit being grounded not when the key is turned on and the above posts, here is something I wrote up for myself. Hope it helps you.


A Tip to Help Diagnose If Stalling is Fuel or Ignition Related


I watch the ammeter as my toe pushes the starter button. If I don’t see the ammeter twitch with each cylinder compression, I stop and install the safety fuse, open the fuel valve or turn the key on! This twitch is referred to as the “Henry Jiggle”. IMHO, ‘driver’ Model A’s should have the November 1929 Service Bulletin wiring change applied, so the primary ignition circuit function is reflected on the ammeter as a negative twitch at low rpms. If your car stalls on the road, or when approaching a stop, before pushing in the clutch, check for Henry’s Jiggle.

If the jiggle is there, the primary ignition circuit is very likely working as it should. Check the secondary circuit spark quality at the coil wire. If Henry’s Jiggle isn’t there, perform primary ignition circuit test procedures as covered in the Les Andrews blue book. Your ammeter is your friend. Check it before exiting your A. It should not show a discharge.

[jerrytocci]

Could be the starter switch. bypass the switch

[Planojc]

If the starter bendix is locked up, when you push it in 3rd gear, you should hear a pop sound when it frees up.

[Robert/Texas]

All this information and suggestions have been interesting and helpful for me, and I thank all of you for that.

I should have thought of tapping on the starter. The 8.3 liter Cummins diesel engine in my old motorhome needed that from time to time.

I bought the ’28 roadster in 1988. It was a project car when I bought it. One of the things I did was to replace the worn-out starter switch with a repro. The repro turned out to be a piece of junk so I ended up repairing the original one as best as I could. This repair has lasted a long time but could be all or part of my problem now.

My workshop is occupied by my ’34 roadster which is waiting for a NOS front spring to replace the broken one. It should come next week some time. I need to get this car out of there before I can work on the A. Also, I’m scheduled for a minor (hopefully) operation next week which could delay things.

My plan is to remove the starter and everything related to it and hope that I can figure out what needs fixing or replacing.

Thanks again, Robert

[rotorwrench]

Sponsored Links (Register now to hide all advertisements)

Don't compare later cars with the Model A. When electrical instruments started to show up in cars, they are turned on with the ignition. This would give a discharge indication whether the ignition breaker was open or not.

Ford did a small change to the coil wiring of the model As on a service bulletin so that the connection with the ammeter would be more sensitive to the ignition system. If a person turns on the ignition with breaker open then there will still be no sign of discharge until the starter is engaged. With starter engagement, the operator should see the ammeter register the opening and closing of the breaker. This is a way of telling the operator that the ignition system is functioning normally. The ammeter can be used it several ways to troubleshoot problems.

[nkaminar]

Robert, Good luck with your (hopefully minor) operation.

[gdmn852]

Hello,had similar problem on my 30 coupe the ring gear on flywheel was worn on bendix would jam into it stalling out the starter,because it was stuck on ring gear. Putting it in gear and rocking it would release the jam up ,and hopefully it would start next time.

[Ed in Maine]

Maybe worn starter brushes? Maybe moving the car allows the brushes to make contact after there is some vibration. First, I would check the grounds. Ed