Keeps running

[Kaiser2boy]

Ok got the brakes fixed, egine runs fine every ones happy.
So I took her out for some fun in the snow up and down the hills on my property what fun.
I go back to the garage and did somthing out of my normal sequence.
I normally turn off the ignition THEN the master cut-off switch from the battery.
This time I accidently turned off the master switch first.
The truck kept right on running!.
I thought there was a problem with the switch so I removed one of the wires running from the switch to the batterys and ,,,it kept running!
How can that be?
It will shut off if I turn off the ignition switch.
It wont start with the master switch off but once running it will run with it off ...

[Charles Talbert]

Ok got the brakes fixed, egine runs fine every ones happy.
So I took her out for some fun in the snow up and down the hills on my property what fun.
I go back to the garage and did somthing out of my normal sequence.
I normally turn off the ignition THEN the master cut-off switch from the battery.
This time I accidently turned off the master switch first.
The truck kept right on running!.
I thought there was a problem with the switch so I removed one of the wires running from the switch to the batterys and ,,,it kept running!
How can that be?
It will shut off if I turn off the ignition switch.
It wont start with the master switch off but once running it will run with it off ...

It is normal for this to happen. It is because the generator is charging; you see the master switch only isolates the batteries, thus while the engine is running, it receives power from the generator. If you want to change this, there is 2 ways to do it; install a diode in the field wire coming from the generator, which works like a check valve letting current flow only in 1 direction; or you can get a master switch with 4 terminals, 2 for battery cables, and 2 for the field wire. That way when the master is turned off, the field wire is disconnected also.

[MoparFreak69]

Great reply Charles. Only thing I will add to maybe clarify a little bit, the master switch only cuts the power from the battery to the dash. Like Charles said the generator is what is keeping power to the ignition coil, backfeeding through the field wire to the ignition switch.

[gusbratz]

dumb question

is this master switch something you added or is it somewhere on my truck and i don't even know i have it?

[Charles Talbert]

Great reply Charles. Only thing I will add to maybe clarify a little bit, the master switch only cuts the power from the battery to the dash. Like Charles said the generator is what is keeping power to the ignition coil, backfeeding through the field wire to the ignition switch.

That depends on how Kaiser has his switch wired. We most often install them in the positive cable between the battery and the starter switch terminal. This kills power to the starter and dash as well since power to the dash is picked up from the starter switch positive. Occassionally we install one in the negative cable in certain situations. Doing it any other way doesn't isolate the full system from the batteries completely, and sort of puts a damper on the intended benefits.

[Charles Talbert]

is this master switch something you added or is it somewhere on my truck and i don't even know i have it?

Master disconnect switches are not original equipment; but are one of the best upgrades that can be added. It is especially smart to install one if your wiring or any electrical component is questionable, also a great theft deterrent.

[Kaiser2boy]

The switch is on the negative side and was on the truck when I got it. It was just the same as the truck I used in the Army back in 67.
After I sent my question in it dawned on me that it was normal to keep running. I remembered that cars back in the 50s &60s only needed a battery to start and then it would run on the generator. I should have rememberd when I was 16 and my first car had its battery stolen and my dad came and jumped it and it started . He put an old glove over the positive cable said DONT LET IT STALL! and drove away.