No Electrical When Ignition Switch is On

[Somemedic]

Was driving 5 he other day when I went to honk the horn and noticed the horn wasn't working. I saw the ignition switch was on but looked at the guages and saw the volt meter was dead... All guages were off... no horn or turn signals.

It was like the switch was off. So now the truck will no longer start. There is no electricity when the switch is on.

Batts are good.... can't find any fuses.

 

[Reaper651]

The troubleshooting TM's and a volt meter will be your two best friends at this point. It sounds like the master switch is probably bad. I have been diagnosing the same issues with my Deuce.

 

[RAYZER]

There are no fuses, but there are circuit breakers on the outer fire wall.

 

[cattlerepairman]

Batteries are ok, you say, so I would start with checking the battery cables, the ground strap to the frame and work my way forward from there. It could be a bad accessory switch ("master switch").
The TM has great step-by-step troubleshooting sections.

 

[73m819]

Check and make sure the master solenoid is working, the ONLY thing the master switch does is activate the master solenoid.

 

[Reaper651]

Check and make sure the master solenoid is working, the ONLY thing the master switch does is activate the master solenoid.

The master solenoid?? Ok now you have me wondering how I missed this in the troubleshooting TM, and how I haven't found it on my truck. Oh great now I have something else to figure out. Thanks for the info. Now I have some more TM reading to do.

 

[Somemedic]

Yeah... I've heard of in line fuses making it into some of the wiring. Thankfully there doesn't appear to be any other than a lighter plug that's installed.

Where's the solenoid? On top of the starter?

As for the ground, it appears to be secure.

I'm liking the bad switch theory. That is the part that gets actuated the most, high probability of failing.

I will report back when I find it. Thanks for the suggestions.

 

[steelandcanvas]

I haven't seen a Master Solenoid in the M35A2 schematics. Could that be a 5 Ton thing Ron? I don't think it's the Master Switch, the horn on a Deuce will work with that switch in the off position. I would start by looing at the connections on the starter relay and the magnetic start relay. Pay close attention to wire #14 and wire #10. By the way, there is one fuse on a Deuce, it's under a little cover on top of the fuel tank. Here is a schematic that might help you.

View attachment WIRING_SCHEMATIC.pdf

 

[pigfoot63]

I think we may be talking about the magnetic starter relay, under exhaust manifold passenger side of engine.

 

[Reaper651]

Ok so I'm not crazy. I don't think there is a "Master Solenoid" But I'm not totally sure. I have never found one on my truck and I am pretty sure no wires from the master switch run to any kind of relay or solenoid. If I remember correctly, one wire goes to the alternator to excite it and the other one goes to the in tank fuel pump and the gauges. But I still have a lot to learn about the Deuce so don't quote me.

 

[R Racing]

Had my power switch go bad in my m35a3 it wasca, odd thing. It worked until you hit a bump then the truck would turn off it drove me nuts til I found out it was the power switch .

 

[EWhytsell]

FYI my horn works with the master switch off.

 

[Pugsley]

I hate the fact that it is called the master or accessory switch yet does neither.

 

[Somemedic]

Today the truck got my full attention. I replaced a few jive ass looking chop jobs and tightened the battery connections. I bumped the starter terminals and the starter began to engage... The 24 volts are there all that is needed is to ground the system.

There isn't however a magnetic starter relay. It was hacked out long before I got it.

Tried replacing the accessory switch with a new one but there's no change.

This isn't nearly as fun as it sounds. Bjorn I'm looking for you

 

[cranetruck]

Here is the wiring diagram and do install the starter relay (it will save your start switch)

 

[cranetruck]

The neutral safety switch may or may not be present. This a general diagram.

 

[randygk]

I've had two intermittent electrical problems on the 1967 deuce that sound similar to yours. One was a wiring harness connector on the firewall near the steering column - had a loose crimp on one wire. Our later deuces didn't have these connectors. The other was a loose connector on the master switch.