DK-40 Starting issues

[seacap04]

Last summer I had a glow plug circuit not working right. Going through the circuit the the relay clicked and I could feel coil pulling down. Kept coming back to relay. Continuity through it when activated. At last measured voltage under load. 12.6 volts in 8.2 out. Bad points. I know you can feel coil pull down but wonder if points have broken off coil and fused across terminals. Do not ignore anything that has been suggested so far. But I would measure for voltage on the glow plug side of this relay with key off, This is the hardest working relay on the tractor.

 

[seacap04]

Your post #29 showed up after I posted #31. kOua kind of says it all. I miss the days that diesels would run without power.

 

[ritcheyvs]

It's a bad to disconnect the battery on a running engine. Sometimes that will blow the diodes in the alternator rectifier, not every time, but some times. If one of those diodes blows in the short-circuit mode, the alternator will drain the battery to the tune of about 2-3 amps (the max field coil current). That would easily kill a battery in a day.

With the engine running and a relatively healthy battery, you should see at least 13.6 volts across the battery terminals and 14-14.5 volts would be more healthy. For a healthy battery that sat uncharged for several hours you should still see 12.3-12.5 volts (maybe more) across the terminals.

If you pull the start relay, the engine won't crank. If you pull the stop relay, you'll meed to stop the engine manually,as you did. If you pull the glow relay, the engine may not start when cold but should start OK at operating temp.

 

[joefromga]

The starter solenoid may be sticky.

 

[tkh159]

Well, now we have what is know as an intermittent. NOT GOOD. They say that He** for an electronics technician is a room full of intermittents with only intermittently working test equipment to attempt to repair them with.

This is true and very aggravating. Time to start by passing safety switches and pulling relays.

 

[tkh159]

It's a bad to disconnect the battery on a running engine. Sometimes that will blow the diodes in the alternator rectifier, not every time, but some times. If one of those diodes blows in the short-circuit mode, the alternator will drain the battery to the tune of about 2-3 amps (the max field coil current). That would easily kill a battery in a day.

With the engine running and a relatively healthy battery, you should see at least 13.6 volts across the battery terminals and 14-14.5 volts would be more healthy. For a healthy battery that sat uncharged for several hours you should still see 12.3-12.5 volts (maybe more) across the terminals.

If you pull the start relay, the engine won't crank. If you pull the stop relay, you'll meed to stop the engine manually,as you did. If you pull the glow relay, the engine may not start when cold but should start OK at operating temp.

Yeah live and learn. I got lucky this time but won't be removing batteries on running engines any more.

 

[tkh159]

Last summer I had a glow plug circuit not working right. Going through the circuit the the relay clicked and I could feel coil pulling down. Kept coming back to relay. Continuity through it when activated. At last measured voltage under load. 12.6 volts in 8.2 out. Bad points. I know you can feel coil pull down but wonder if points have broken off coil and fused across terminals. Do not ignore anything that has been suggested so far. But I would measure for voltage on the glow plug side of this relay with key off, This is the hardest working relay on the tractor.

Are you referring to the timer relay and the glow relay?

 

[tkh159]

The starter solenoid may be sticky.

How would we test this? Wonder if I can buy just the starter solenoid and not the starter and solenoid?

 

[tkh159]

7:30pm yesterday battery voltage was 12.73

7:30am today battery voltage was 12.69

 

[k0ua]

7:30pm yesterday battery voltage was 12.73

7:30am today battery voltage was 12.69

Good fully charged Battery, if that is the static battery voltage. Charging voltage should be about 14.1 or so after a startup, slowly tapering off as the battery comes to a full charge. Usually around 13.8 to 13.9 .

In cold weather hitting the glow plugs will drag it down to 10.something depending on how cold and how good your battery is. But as soon as it starts it should go to about 14.1 or 14.2 or so