Need some wiring help

glinke · Mar 7, 2011

I have a '62 40403 - heavy duty industrial. It's a 4 cylinder gas. It has been converted to 12-volt negative ground with a three-wire alternator. It has a 4-terminal solenoid. Currently the positive from the battery goes to the front terminal as well as a wire going to a pushbutton switch (broken) on the dash. Another wire comes from the other terminal of the switch to the "s" terminal of the solenoid. The "i" terminal is empty. The back terminal has a cable going to the starter. Jumping from the front terminal to the "s" terminal spins the starter.

Since the switch is broken, I want to go back to the original starter button down by the shifter. I have a new starter button installed. The transmission is in neutral. If I hook either of the wires from the old switch to the new one and press the new switch, nothing happens. The position of the ignition switch - also not original - does not make any difference.

I want it to work like the original - ignition switch on, transmission in neutral, press starter button, starter turns.

Any help would be greatly appreciated!

Oh, If I want to replace the wiring harness, do I need a 6-volt one - what it was or a 12-volt one?

I have worked on vehicle electrics before, but none as chopped up as this one.:confused2:

Gayle

Soundguy · Mar 7, 2011

i'd get the correct solenoid. if someone was using a dash mounted starter switch they changed the solenoid to an automotive style.

you need an isolated base style 4 post solenoid.

bat wire to one big terminal.. other big terminal to starter.

wire from coil side of ignition switch to one small terminal, other small terminal to trans mounted (grounding) switch .

key on provides power to the coil in the solenoid.... pushing the thumb button grounds it..

simple

soundguy

Soundguy · Mar 7, 2011

ps.. a napa st541 or 542 is the 4 post solenoid that can be made to work.

soundguy

moship · Mar 7, 2011

Gayle,

You need 12 volts to the S terminal on the starter solenoid for it to engage the starter. You have already proven the solenoid works which is a start.

What you need to do:
Verify 12 volts is present before and after each switch in the circuit and finally to the starter solenoid. To do this you will need a volt meter or a 12 volt test light. If you do not own these basic electrical tools it is time to break open the wallet and purchase. Trouble shooting wiring without is a waste of time and only leads to replacing wires or switches until the problem is resolved.

It is a relatively simple problem to solve.

Further information about the replacement key switch would be helpful.

Report back and someone else or I will help.

Soundguy · Mar 7, 2011

he NEEDS the correct isolated base style solenoid.. not a key-start solenoid. the correct solenoid is not a ignition bypass style.

soundguy

moship said:
Gayle,

You need 12 volts to the S terminal on the starter solenoid for it to engage the starter. You have already proven the solenoid works which is a start.

What you need to do:
Verify 12 volts is present before and after each switch in the circuit and finally to the starter solenoid. To do this you will need a volt meter or a 12 volt test light. If you do not own these basic electrical tools it is time to break open the wallet and purchase. Trouble shooting wiring without is a waste of time and only leads to replacing wires or switches until the problem is resolved.

It is a relatively simple problem to solve.

Further information about the replacement key switch would be helpful.

Report back and someone else or I will help.

moship · Mar 7, 2011

Perhaps I am a bit confused. The OP said supplying 12 volts to the S terminal caused it to start. He did this by jumping the 12 volt battery supply to the S terminal and the starter turned over. That is why I made the statements in my post. There are solenoids that require 12 volts to a termianl marked S, but I must admit I'm not familiar with this particular tractor.

It sounds like the tractor wiring was heavily modified and not stock.

If I misread the post, sorry for that. The OP was somewhat vague in what he has. A few pictures and/or wiring sketch of the current situation could clarify and help with the situation.

glinke · Mar 7, 2011

Soundguy, I have not heard of different types of 4-post solenoids before. Thanks for the info. I have not removed the old one to see if it has any markings. I'll do that, too.

Moship, I have both a multimeter and a voltage indicator light.

I'm not near the tractor right now, so pictures are an issue. I know it has the wrong ignition switch on it now as there are three terminals instead of just two on the original. It has so many wires of the same color it is hard to trace where any one of them go. It's like they only had red wire when they did the rewire job. That's why I asked about replacing the whole harness. At least then the wires would be the right color.

When I got the tractor one wire went from the starter button to the front post on the solenoid. Another (the same color) went from the other side of the starter button to the S post on the solenoid.

The tractor is basically a 4000 with the external frame and the non-adjustable front end. It's a lot like an 1801.

Soundguy · Mar 8, 2011

the 4 cyl 01 style ford setup with a 4 post solenoid requires key switched power to one small terminal, and switched ground to the other small terminal.

the tranny thumb switch is ground when pushed.. and is connected to one small terminal.. key on is the powqer connected to the other.

IE.. 4 4 posts on the solenoid, 2 are bat to starter.. the other 2 are the solenoid coil. this is an isolated base relay.

standard 'bypass' 4 posts solenoids use the mounting base for ground, and one small terminal for power.. when power comes in from.. say a key-to-start switch, it connects the big terminals. the other small terminal is a bypass to provide powwer to a coil bypassing an ignition resistor.

helps to be familiar with an application before offering advice on it.

a 4 poster that needs power only to start is the incorrect solenoid, or is the correct one, wired wrong!!

i provided the correct numbers for a replacement solenoid...

soundguy

moship said:
Perhaps I am a bit confused. The OP said supplying 12 volts to the S terminal caused it to start. He did this by jumping the 12 volt battery supply to the S terminal and the starter turned over. That is why I made the statements in my post. There are solenoids that require 12 volts to a termianl marked S, but I must admit I'm not familiar with this particular tractor.

It sounds like the tractor wiring was heavily modified and not stock.

If I misread the post, sorry for that. The OP was somewhat vague in what he has. A few pictures and/or wiring sketch of the current situation could clarify and help with the situation.

glinke · Mar 9, 2011

I will make a NAPA run! I also have a new key switch on order.

BTW, where is the junction block mounted? Mine is long gone. That's also on order.

Thanks!