ignition switch question

[jocko165]

I have an old ford 555 backhoe. the tractor will start by pushing the starter button no matter what the position of the key in the ignition switch. is this normal? seems to me the ignition switch may be bad. wont this drain my battery if I cant turn the ignition off?

 

[Delmer]

wont this drain my battery if I cant turn the ignition off?

If the battery doesn't drain in a matter of hours then the start button isn't run off of the ignition switch. Old, diesel? Solenoid in the injection pump or cable shut off for the engine? If you have a manual engine shut off, then the "ignition" position on the key only controls the alternator, unless that's a one wire original or conversion.

I can't believe it was original that way. Supply the starter button from a switched terminal, or add a relay if the starter solenoid doesn't like to work through the key switch.

 

[jocko165]

a couple more questions. is this tractor supposed to have a pushbutton starter switch AND a keyed ignition switch? I have the keyed ignition in my hand and when I hit the pushbutton the tractor started. im guessing somebody in the past has bypassed the keyed ignition, but again isn't this a constant drain on the battery?

 

[Delmer]

You answer my question first. Is there a pull knob to shut it off, or is there a wire going to the injection pump?

I don't know Ford backhoes, but it's common for old tractors to have a key and a push button start, but I've never seen the push button able to start the engine with the key off. That part is "jethroed".

 

[jocko165]

pull knob to shut off. I haven't had time to trace wires but I wonder if the ignition switch controls anything or if its been completely bypassed. my big concern is if it will drain my battery. as long as I can start the hoe im good

 

[fpgm04]

You are not going to drain a battery through a switch that is switched-off.

However, if your vehicle has been “customed” wired, then there could certainly be circuits that have been wired around the switch and therefore will always have power with the key off, and could drain your battery.

An easy test to see if you have any battery drain is to use a multimeter that has DC current reading ability.

With engine off, key off, and all accessories off (example lights, fans, radio, etc) carefully disconnect one of the battery cables and insert your multimeter configured to read DC current. If the meter registers current, you have something draining your battery. Do not attempt to start the machine, nor even key on, with your multimeter in circuit as it will likely damage your meter or best case blow its fuse.

 

[Delmer]

Obviously the injection pump doesn't need power with a manual shut off. The only other things I'd wonder about would be the alternator and any electric gauges. If the alternator is a one wire, or wired through the switch, then you're probably fine. Probably not any fancy gauges either?

Easy enough to see if it's draining the battery, does it start in the morning?