Keyed ignition switch for M35A2, blah blah blah

[Blythewoodjoe]

I have looked for hours at wiring diagrams and threads. I searched until I am sleepy. So despite the fear that comes from posting a question that some one may have answered in a thread years ago using improper English (or proper English, I am from South Carolina), or words or phrases I have not thought of, I ask a question.

I have looked over the wiring diagram for a M35 and there are 4 wires going to the ignition switch. Two wires are labeled "11" and appear to tie together somewhere before they reach the switch. Not sure why they do this but they appear to bring 24 volt power to the switch. This is my first assumption and opportunity for someone to correct me.

One wire labeled "27" appear to feed voltage to most of the stuff needed to run the truck. The starter button gets power from this wire (second chance to correct me). Last wire is labeled "1". You know, the loneliest number. This sends power to the alternator regulator, again I assume the power flows from the switch to the regulator.

Based on the above assumptions, I assume when you switch the switch on you close two independent circuits. One circuit provides power from one of the "11" wires to the "1" for the regulator. The other provides power from the other "11" to the "27" for everything else.

Based on the above assumptions (you will get tired of that phase soon) can you take a traditional 4 wire keyed switch and connect both "11"s to the battery terminal, the "1" to the acc. terminal and the "27" to the run or ignition terminal? This would keep the two circuits separate. You could also take the wire from the start button and attach it to the start terminal.

Based on the above assumptions I can think of a couple of problems. First off, if you use the start terminal on the keyed switch you loose power to the "acc." terminal. This might effect the alternator. Unlikely but possible. Second, you would be able to power up the alternator regulator with out the truck showing anything "on". This would only be a problem if some dummy switched it to acc. and left the truck.

You could not use the acc. post for the "27" wire because when you hit the starter, you would loose power and the starter would disengage. At least most of the aftermarket switches I have used kill acc. power during start mode. Last option would be to tie "27" and "1" together on the ignition terminal. Any thought's?

 

[clinto]

I guess it depends upon what you're after:

Is the purpose of the keyed switch to keep people from turning on the electrical system, or to keep someone from starting it?

On the main power switch, constant power is fed to A and C. When you turn the switch, power is sent to B and D. B & D sent power to the in-tank pump (654) and the dash gauges (27).

So if you interrupted the "B" circuit, no juice would go to the starter button.

But the switch would still be sending energizing the alternator field.

After looking at the deuce system, I believe the best choice is a heavy duty keyed switch that kills the entire truck. Something that is North of the main power switch.

You could hide this switch anywhere you want: In the cab, in the battery box, etc.

 

[Blythewoodjoe]

I like to simplify things and my original concern was keeping someone from starting the truck easily. Replacing the factory switch with a keyed switch would be the cleanest way to do this. I had thought about just putting a switch on the starter button but that would not keep someone from switching the original switch on and running the battery down. This would be on the bobber I am planning to sell and I just wanted to make the truck a little more user friendly. I hate the two switches on my 5 ton and it's easy to leave one switched on. My goal is to dummy proof it too.

I'm a fool to mess with it. I plan to sell the truck in a few weeks and I really need to get in the habit of letting things go when I plan to sell something. I just worry about people messing up and do all I can to prevent that. I imagine the new owner stopping to get lunch on the way home and some kid walking up to the truck and hitting the starter button and running over a van full of nuns. I wish I could afford therapy.

Crazy Joe

 

[gringeltaube]

This is what I did on two of my trucks: http://www.steelsoldiers.com/showth...Switch-Install&p=815506&viewfull=1#post815506


G.

 

[peashooter]

Somewhere on here I have info on that 4 wire lever start switch. Mine had it but was later changed changed to a 2 wire push button per some directive because of problems with the 4 wire unit. 2 of the wires on my original 4 wire switch were to activate a couple warning lights before it started so you could verify the lights worked (just like when you start your car and all the dash lights come on right away).
I put a key interrupt switch inline with the +24v going to the starter button. It was an easy install and should prevent most folks from using the starter unless they put a lot of time into tracing the wires. I've also got a battery disconnect switch in the battery box.

edit- I misunderstood your 4 wire switch question. Forget the first paragraph above.

 

[rustystud]

Somewhere on here I have info on that 4 wire lever start switch. Mine had it but was later changed changed to a 2 wire push button per some directive because of problems with the 4 wire unit. 2 of the wires on my original 4 wire switch were to activate a couple warning lights before it started so you could verify the lights worked (just like when you start your car and all the dash lights come on right away).
I put a key interrupt switch inline with the +24v going to the starter button. It was an easy install and should prevent most folks from using the starter unless they put a lot of time into tracing the wires. I've also got a battery disconnect switch in the battery box.

edit- I misunderstood your 4 wire switch question. Forget the first paragraph above.

Peashooter, your gauge cluster looks so cool ! I'm glad your still making these. I can't wait till I get mine !!!

 

[Blythewoodjoe]

OK, here' what I did. I tied the two "11" wire to the battery post on my keyed switch. I run them separate from the factory plugs to the switch. Seems un-necessary but I did it anyway. I run the "1" wire from the alternator to the "ACC" post. The "27" wire to the "IGN" post. This provided power to the "27" wire while the switch is in the start position. I ran the "starter" post down to the factory starter push button plug and plugged it into the side that runs to the starter. It seems to work well. I used an old wiring harness to get plugs for the wires so I could just plug the original ignition switch wires into these wires. I can put the original switch back in if this doesn't work out. Here's a picture I just drew.

 

[Skoal_Bro]

I have looked for hours at wiring diagrams and threads. I searched until I am sleepy. So despite the fear that comes from posting a question that some one may have answered in a thread years ago using improper English (or proper English, I am from South Carolina), or words or phrases I have not thought of, I ask a question.

I have looked over the wiring diagram for a M35 and there are 4 wires going to the ignition switch. Two wires are labeled "11" and appear to tie together somewhere before they reach the switch. Not sure why they do this but they appear to bring 24 volt power to the switch. This is my first assumption and opportunity for someone to correct me.

One wire labeled "27" appear to feed voltage to most of the stuff needed to run the truck. The starter button gets power from this wire (second chance to correct me). Last wire is labeled "1". You know, the loneliest number. This sends power to the alternator regulator, again I assume the power flows from the switch to the regulator.

Based on the above assumptions, I assume when you switch the switch on you close two independent circuits. One circuit provides power from one of the "11" wires to the "1" for the regulator. The other provides power from the other "11" to the "27" for everything else.

Based on the above assumptions (you will get tired of that phase soon) can you take a traditional 4 wire keyed switch and connect both "11"s to the battery terminal, the "1" to the acc. terminal and the "27" to the run or ignition terminal? This would keep the two circuits separate. You could also take the wire from the start button and attach it to the start terminal.

Based on the above assumptions I can think of a couple of problems. First off, if you use the start terminal on the keyed switch you loose power to the "acc." terminal. This might effect the alternator. Unlikely but possible. Second, you would be able to power up the alternator regulator with out the truck showing anything "on". This would only be a problem if some dummy switched it to acc. and left the truck.

You could not use the acc. post for the "27" wire because when you hit the starter, you would loose power and the starter would disengage. At least most of the aftermarket switches I have used kill acc. power during start mode. Last option would be to tie "27" and "1" together on the ignition terminal. Any thought's?

Funny Jose. 2021 and this is just what I needed. Good Question