starter switch

[keith1955]

I went to start my ford jubilee the other day and when I pushed the starter switch the starter began to crank as normal , but when I let off the switch it continued to crank. I had to unhook the ground post to get it to stop. Now when I connect the battery it cranks on its own . This tractor sits most of the time. Starter switch bad or possibly something else ?
thanks

 

[souNdguy]

here's the test..

disconnect the solenoid from the starter that way you aren't grinding on the starter needlessly.

the thumb swich is just a switch to ground, and has a wire to the relay.. the relay coil is hot fromt he battery, and pressing the thumb switch provides ground.

this will tell you if relay is bad.. ie..small terminal is shorting to case on relay, or if wire to relay is shorting to the chassie, or the thumb switch is shorting across it's contacts.

hookup batter.. remember to remove wire to starter.

if it clicks when you hook up battery, first disconnect wire from thumb button.. if that makes the solenoid relax, then you know the thumb button is at fault.. if it does not relax, disconnect the small wire from t he relay, if that makes it relax, thenthe wire is shorting to ground. finally, if the relay is pulled in with no small wire hooked to it and only relax's with the bat post off, then the solenoid coil cround ( small post ) is shorted to case.

either repalce the solenoid, if that is it.. if it is the wire, run a new one.

if it is the thumb switch, try pressing the button and spinning it vigoresly back and forth about a minute to polish contacts.. perhaps even spray some carb cleaner using a straw up under the cap and then spin it again while pushed.

re test.

if the thumb switch stays bad, just replace it.

you can find a good article on repalcing the switch at the n-news site.. bruce and i co-wrote one.. the short of it is you will be pulling the trans top cover.. replacing a gasket, bending some locking tabs down, removing a retainer nut, r&r the switch with gasket, re-nut, re bend the retainer, then repalce cover after cleaning deck and cover and installing new gasket. i reccomend having tractor in neutral before you start so you can get the shifter back in easilly. it's a 30 minute job with some wrenches and cleaner.. and a couple other small tools.. there is a spring under the cover at the rear oft he shifter cover under a small tab.. just lift it up slowly so it don't stick tot he cover then fall inthe trans.. remove it when you clean the deck, then repalce it when you add the gasket and put the cover on..

it's a 2 ont he shade tree mechanic scale of 1-10 10 being hardest.

if you can change yer own oil.. you can do this.

soundguy