Glow plug question

[Watersgraphics1]

My Kioti tractor seems to turn over and start when it is cold out, or hot out, but not on a cool morning. The glow plug indicator comes on, goes off, but the motor will not turn over. Could it be a bad sensor or relay?

 

[rScotty]

My Kioti tractor seems to turn over and start when it is cold out, or hot out, but not on a cool morning. The glow plug indicator comes on, goes off, but the motor will not turn over. Could it be a bad sensor or relay?

Could be a sensor or relay.
But the glow plugs use a lot of battery power in a hurry - and might not be leaving enough for the starter. Or the indicator turning off might just mean the battery is flat. In either case, my first guess would be the battery is flat, second guess would be corrosion in the connectors to the battery terminals.
rScotty

 

[Watersgraphics1]

Yeah, I have cleaned the battery connections and checked the volts, 12.42V.

 

[rScotty]

Yeah, I have cleaned the battery connections and checked the volts, 12.42V.

Good on you. And it helps that you have a VOM.
Is the solenoid to the starter engaging?? On mine I know it works because that is what makes the loud "click" when you first turn it to to crank. A loud click, and then it cranks. The trouble is that solenoid passes so much amperage that points inside eventually burn and quit conducting. Still clicks, but no crank.
Of course if it doesn't click at all, then it is either the solenoid - or its dedicated fuse - or one of the safety switches (like the PTO or seat switch) OR the ignition switch itself. Those are all in series, so you can check if each is getting voltage.

 

[Mtsoxfan]

If it's fine at cold temps, chances are that battery/starter are not the issue...

 

[Watersgraphics1]

Good on you. And it helps that you have a VOM.
Is the solenoid to the starter engaging?? On mine I know it works because that is what makes the loud "click" when you first turn it to to crank. A loud click, and then it cranks. The trouble is that solenoid passes so much amperage that points inside eventually burn and quit conducting. Still clicks, but no crank.
Of course if it doesn't click at all, then it is either the solenoid - or its dedicated fuse - or one of the safety switches (like the PTO or seat switch) OR the ignition switch itself. Those are all in series, so you can check if each is getting voltage.

Just tried it again, not even a click. Tried boosting it and same. It is 78 degrees here. I wonder if the glows plugs always warm up a bit, even in hot weather. Don't understand why the saftey

 

[Watersgraphics1]

Sorry, why the safety switches or key switch would work sometimes and then not. Called a mobile mechanic out here one time and of course it started tight up.

 

[ericm979]

Sometimes electronic parts can go bad in a way that makes them fail intermittently.

It there's not even a click its not the glow plugs. When those go bad or don't get power, the engine turns over but is hard or impossible to start.

It sounds like an electrical problem involving the battery or charging system. 12.4v is low. It should be in the 13s. I'd start by charging the battery. That may take care of it or there may be another problem like a cell in the battery is going bad or the alternator is not charging the battery enough.

If the battery can't be charged to 13v then it's probably dying. If it holds a charge then I'd look to the alternator. Check the belt tension. Charging voltage at idle should be at least 13.5.