F134 Starter Switch

My M38A1 has a starting problem. It has not been started since I rewired it. I used a wiring harness specific to M38A1s.

According to the schematics (see pics) everything is correct. A multimeter shows 24 volts at the battery and starter. When the key is turned to the on position all of the gages work so juice is flowing between the starter to the ignition switch. I also have 24 volts at the distributor.

The starter switch is on top of the starter and is activated with a foot plunger. When depressed I get absolutely nothing. I've confirmed the foot plunger is aligned properly and the rod is being pushed into the switch correctly.

All of this has me thinking it's the starter switch unless I'm missing something. Before spending $120+ on a new switch which will take 10 days to arrive, is there a way to bench test the switch? I've had it apart and, while the contacts aren't perfect, they look clean enough to work.

 

Correctly as in you're positive it pushes in far enough?

 

Yes

 

The only other thing is like Ron said try jumper cables across the switch. You are obviously aware that the key doesn't have to be on for the starter to turn over, right?

 

Can you try a test light across the terminals? Do you have a matching voltage test light?

 

Great suggestion. I'll try it when I'm back out there next weekend.

Yes.

 

His does. A picture confirmed it. We both know a key switch isn't stock.

 

The ignition switch is not in question. It's the starter switch. I suppose I could generically refer to it as a solenoid but it's actually a switch that is activated by the plunger. Everything is line ups correctly and the plunger fully extends when depressed. I've also manually pulled the lever that the plunger pushes without anything other than I can hear the contacts inside the switch hitting each other.

Next weekend I plan to jump the 2 terminals as previously suggested. If the starter cranks I'll know it's definitely the switch. I opened the switch up to examine it and it looks fairly simple. The contacts don't look out of the ordinary but I don't know what ordinary really is.

All of the replacement switches that I've been able to find appear to be NOS so I doubt the contacts by themselves are available.

 

I assume that it worked previously but the wiring needed help is the reason you rewired it? If so it would seem you would at least get some indication of the switch working.

 

There's one lug on a cable that's going to the switch that looks like it got toasty hot, I'd pull it off & go at it with some sandpaper on the flats just to make sure you get good continuity through to the switch post.

 

Could be but the stud looks fine.

 

I think that is just the way it is. I've seen some others somewhere like that....just don't remember where.

 

The lug is much cleaner than it looks. It was cleaned up on a wire wheel. The multimeter shows 24 volts at the stud so it's conducting well.