DK-40 Starting issues

[Coyote machine]

That's funny. Well I ordered a workshop manual and parts book specific to my DK40 in hopes that I hook up the two relays correctly. They both look the same and can fit properly in the female connection. Only difference one is 50 amp the other 70 amp.

I truly want to roll the dice and put the 70 amp on #1 ( from picture ) as the gauge of wire is bigger but I don't want to put a relay in the wrong place and cause further damage.

Glow plugs aren't working either that's another topic.

Glad you liked the humor- it helps in these situations, IMHO. Stress reducer.

It would make sense that the heavy wiring would be where the glow plug relay connects. Why not trace the wire(s) from the heavy wiring to the glow plug wiring on the engine, ( the glow plug's buss) to see if it is connected. You could do this via the resistance, (Ohms) scale on your meter.
I wouldn't be surprised if the glow plugs are burnt out from the current short through the burnt relay and to the plugs on the buss. You can check those with a meter too.
I would think you could put the 70 amp relay where the burnt relay was, IF that location has the heavier wiring, AND if you are sure the burnt relay was for the glow plugs, (I don't recall what you said about which relay's location, etc.)
I don't think it would be rolling the dice to do what you've suggested; after all you won't be installing a rusted out relay, you'll be installing a known to be new one. And if there's smoke, disconnect the battery ground cable, having loosened it first. Wait a minute or so before trying to start the tractor to see if any firewall relay gets warm without doing anything with the key switch. If everything looks good try starting it and see where it goes. Then disconnect the battery and fix the glow plug circuit (replace plugs, as needed, IF they prove defective, (open circuit when tested).

 

[tkh159]

Glad you liked the humor- it helps in these situations, IMHO. Stress reducer.

It would make sense that the heavy wiring would be where the glow plug relay connects. Why not trace the wire(s) from the heavy wiring to the glow plug wiring on the engine, ( the glow plug's buss) to see if it is connected. You could do this via the resistance, (Ohms) scale on your meter.
I wouldn't be surprised if the glow plugs are burnt out from the current short through the burnt relay and to the plugs on the buss. You can check those with a meter too.
I would think you could put the 70 amp relay where the burnt relay was, IF that location has the heavier wiring, AND if you are sure the burnt relay was for the glow plugs, (I don't recall what you said about which relay's location, etc.)
I don't think it would be rolling the dice to do what you've suggested; after all you won't be installing a rusted out relay, you'll be installing a known to be new one. And if there's smoke, disconnect the battery ground cable, having loosened it first. Wait a minute or so before trying to start the tractor to see if any firewall relay gets warm without doing anything with the key switch. If everything looks good try starting it and see where it goes. Then disconnect the battery and fix the glow plug circuit (replace plugs, as needed, IF they prove defective, (open circuit when tested).

Well did the logical step and put 70amp relay on the larger gauge wires and vise versa but didn't hear the warming sound of glow plugs.

Correct me if I'm wrong but when I use to start the tractor in the winter I'd hear clicking while the glow plug indicator was lit up and the tractor would start without any issue.

But now this year no clicking and tractor struggles to start.

What I'm asking should I be hearing any sounds from the preheat process? Even the sound of ticking as the metal expands from heat?

 

[Coyote machine]

Yes, you could possibly hear the plugs working IF the circuit is completed by current passing through the glow plugs. But, if the plugs are dead, there would be no sound because there is nowhere for the current to flow. Time to test the plugs.
Does the glow plug light light up?
It would be harder to start without the plugs working in colder weather, so what you're finding makes sense that the plugs may be bad. DON'T use starting fluid/ether to start your tractor.
At least there are no flames or smoke yet!

 

[ritcheyvs]

Have you measured the voltage at the glow plug buss bar, both with the key glow and in crank? If not, you are just guessing, It could be the actual plugs, the relay, the preheat controller, the wiring, or even the key switch. Do some tests. Can you "feel" the glow relay click in when the switch goes to glow (may need a helper)? Do the wires and connectors look OK and have you checked continuity or measured voltages to be sure the power is getting through? The circuit looks quite simple so a little troubleshooting with a volt meter should pinpoint your problem.

 

[tkh159]

Yes, you could possibly hear the plugs working IF the circuit is completed by current passing through the glow plugs. But, if the plugs are dead, there would be no sound because there is nowhere for the current to flow. Time to test the plugs.
Does the glow plug light light up?
It would be harder to start without the plugs working in colder weather, so what you're finding makes sense that the plugs may be bad. DON'T use starting fluid/ether to start your tractor.
At least there are no flames or smoke yet!

The indicator light does illuminate when the key is turned to the ON position. It also flickered on and off when I unknowingly tried to cold start the engine.

Well next project will be the glow plugs I suppose to see if they are good or not. Along with tracing the wires from the relays to ensure proper location of tje glow plug.

I do want to point out and guess about something though. The rusted out relay possibly was my reason for some no starts and draining of the battery as the plug was stuck closed therefore current continuously flowed draining the battery.

HOWEVER this rusted relay could have been closed shut supplying current to the glow plugs and buring them out. I say this cause I had no trouble on starting the tractor last year in either 80 degree or 40 degree weather.

On thr other hand the rusted out relay could be the starter relay???

The only thing I can say for certain is that the stop relay has and does work fine. I want to guess that the stop relay has the smallest of prongs of the three as pictured in my previous post.

 

[ritcheyvs]

I don't think you have a separate stop relay on the firewall (as do later models). I think your stop solenoid is controlled directly by the timer relay, which is a box with a short seven wire "pigtail" ending in a connector. It looks like the timer relay may be under the instrument panel on the right side, but it's hard to be sure from the crappy manual. But the SS works so it really doesn't matter except the third relay on the firewall is for something else (not SS).

When you turn the key to glow, you should be able to "feel" the relay latch if you are holding the right relay. This relay should engage (with key in GLOW) if the preheat controller is working or not. And the glow plugs should be energized when that relay closes, regardless of what else is happening unless wires are damaged..

 

[k0ua]

Another quick easy way to check the glow plugs is by pointing a infrared thermal no contact thermometer at them to see if they heat up. But a simple voltage check on the buss would be my first easy check.. Would only take a few seconds.

 

[tkh159]

I don't think you have a separate stop relay on the firewall (as do later models). I think your stop solenoid is controlled directly by the timer relay, which is a box with a short seven wire "pigtail" ending in a connector. It looks like the timer relay may be under the instrument panel on the right side, but it's hard to be sure from the crappy manual. But the SS works so it really doesn't matter except the third relay on the firewall is for something else (not SS).

When you turn the key to glow, you should be able to "feel" the relay latch if you are holding the right relay. This relay should engage (with key in GLOW) if the preheat controller is working or not. And the glow plugs should be energized when that relay closes, regardless of what else is happening unless wires are damaged..

I can put my finger in the timer and feel it click at the same time as the stop solenoid clicks/moves.

Time to get some gator clamps with the multimeter or get another set of hands.

 

[tkh159]

Another quick easy way to check the glow plugs is by pointing a infrared thermal no contact thermometer at them to see if they heat up. But a simple voltage check on the buss would be my first easy check.. Would only take a few seconds.

Koua I'm lacking the thermal reader as I just don't seem to have one of those on hand HA!

So the test can be done also by placing the multimeter on the buss or the glow plugs themselves?

 

[k0ua]

Koua I'm lacking the thermal reader as I just don't seem to have one of those on hand HA!

So the test can be done also by placing the multimeter on the buss or the glow plugs themselves?

Well, you can test to see if voltage is being provided to the glow plugs thru the relay contacts and that the wiring is functional also, but not that the glow plugs are making use of that voltage. if they are burned out, they won't draw any current or make any heat. I just bought a thermal remote spot thermometer it was about $17.

Amazon.com: Etekcity Lasergrip 774 Non-contact Digital Infrared Thermometer, Yellow/Black: Instant Read Thermometers: Kitchen & Dining