450 jd dozer

[rkoronka]

My dozer will now not shut off with the key switch. I bought it with the top wire on the alt. clip on the side of the alt. not hooked up.When I hooked the wire up to the key switch post where the terminal has no voltage when the key is off.I have to get a screw driver and short the injector pump silinoid to kill the engine. Any help would be much thanked

 

[PD Mechanical]

The wire on the ijection pump should be live when the key is on and dead with the key off. Could be someone has modified the wiring or some of the wires may be shorted across each other somewhere. Steve.

 

[JDemaris]

That's common.

Sounds like the alternator and key-switch circuit is hooked up wrong. Original alternator should be a Motorola - is that what's on there?

Your alternator is backfeeding to the injection pump once it starts charging - regardless of key-switch position. There are several ways to fix. Installing a diode is the cheapest and easiest.

1. Install a diode in the wire feeding field current to the alternator.

2. Install an ignition swith that has an ACC and a IGN terminal. Hook the alternator field circuit to one, and all over IGN stuff to the other. That way the two circuits are totally isolated when the key is off.