testing solenoid on starter motor

[BigRol]

The battery positive goes to ground and the negative completes the connection with whatever. hard to wrap your mind around it I know but that's the way it was in the old days. Google it for some interesting schematics.

 

[whiterose]

The battery positive goes to ground and the negative completes the connection with whatever. hard to wrap your mind around it I know but that's the way it was in the old days. Google it for some interesting schematics.

Oh Ok that is an old one.
Still everything applies just use the same method except the neg is the live now or- 12 from a positive frame/chassis/starter body etc.

In Ac at the power station there are in effect 2 wires from the generator neither one 'live.
They connect either to ground then the other is live to ground.
Same with the battery if they connect the pos to ground you can think of the neg as 'live' even though it would show as -12. Modern systems connect neg to ground and the pos is +12 volts to ground.
Bulbs etc do not care if they connect to ground and a pos wire. They are just as happy and will work from a pos chassis and a neg battery wire. There is 12 volts between either way.

 

[Tx Jim]

Ya, I just noticed it, I wonder if they just made a mistake with the signs on the battery.

A lot of tractors were positive ground before the advent of alternators. JD's were changed to negative ground in '69