Sparking at starter switch
 

Yesterday we drove the 1931 pickup. Started four or five times without any issues. Last night when I attempted to start the vehicle to put in the garage. While holding the starting foot pedal down I only got some arcs below where the foot pedal rod connects to the starter switch.

Removed the starter this morning. Took off the starter switch and band. Bendix was free on shaft, brushes were worn about half, and starter rotated by hand easily. Cleaned the copper button on top of starter. Put the starter back together less the starter switch. Got jumper cables and clamped positive cable to bolt hole lug and touched negative cable to copper button on starter. Started spun as expected. Put the starter switch back on starter and attached to engine. Pressed the start pedal and got the same arcing as before. No attempt for the starter to rotate.

What are the symptoms of a faulty starter switch? Any other ideas?

Thanks in advance.
Charley

Re: Sparking at starter switch
 

Sound like the starter switch is not isolated and the switch is short to ground?

Re: Sparking at starter switch
 

replace the cardboard insulation inside the starter switch .

Re: Sparking at starter switch
 

Both Ferrell and Purdy are right. I also put a piece of rubber gas line over the starter push-rod, it insulates, quiets and blocks out hot air.

Re: Sparking at starter switch
 

If it is a reproduction switch, that is the problem. The case of a replacement switch is more rounded at the top, and can short out.

Re: Sparking at starter switch
 

Charley,
These all sound like good advice. Big John and I talked about your problem the other night. Let me know if I can help.
Marty

Re: Sparking at starter switch
 

Here is a picture of a repro switch I robbed the internal parts from to rebuild my original.

You can see the cardboard insulator and also the plastic insulator that fits into the plunger and insulates it from the copper contact. I don't know what material the original used for the plastic insulator, mine was missing.

Re: Sparking at starter switch
 

Purchased a new starter switch and that fixed the problem.
Appreciate everyone's help.
Charley