JD X749 Dying after 30-45 minutes

[Mike VS]

MAYBE, MAYBE, MAYBE........
Had a minute to go out and look for a relay. At first just 4 fuses and nothing else. Then looking up above tucked away was a rubber boot that was in fact a relay, so I lightly put my hands on it to check the connection which was firmly in place. That's when I tried to start it............Nothing, no dash lights, no starter, NOTHING! I grabbed it firmly unplugging it and while the connections were extremely clean, when I plugged it back in it started fine.
So, this could have been disconnecting just enough to stall it. I feel real good about it and won't know until next week when it's grass time (I hate to just run it for an hour without doing something) It could be just that connection or the relay itself but I think I'm close. I'll keep you all posted!

 

[Diggin It]

Theory of Operation back there shows the Hold circuit at a mere 1/2 amp. Doesn't seem like there should be a relay for that. The Pull circuit at 30 amps would need one. But again, does anybody have a schematic they can post?

 

[ruffdog]

There are what looks to be 2 square relays up under the left screen panel under the throttle lever. They are above the fuse box.

edit....Ha! I see Mike was out looking at his tractor while I was too.....funny. :laughing: I hope you found something Mike!

 

[ruffdog]

Here's another JD overheat thread...
https://www.tractorbynet.com/forums/john-deere-lawn-garden/355570-deere-site-reviews-indicate-x754-2.html

And another.....

https://www.****************.com/threads/x749-diesel-shuts-off-after-20-minutes.169474/

 

[Mike VS]

There are what looks to be 2 square relays up under the left screen panel under the throttle lever. They are above the fuse box.

edit....Ha! I see Mike was out looking at his tractor while I was too.....funny. :laughing: I hope you found something Mike!

Yup, I did find something, read my last post. And I only found one relay exactly where you said.

 

[Mike VS]

And another.....

https://www.****************.com/threads/x749-diesel-shuts-off-after-20-minutes.169474/

I couldn't open that link.

 

[crazyal]

Hopefully you got it.

 

[AndyMA]

I have the service manual. I'm trying to attach the wiring diagram pdf

AndyView attachment JD X748 Wiring Diagram.pdf

 

[ruffdog]

So there are 2 relays, one for the glowplugs and one for the fuel solenoid.

 

[Mike VS]

So there are 2 relays, one for the glowplugs and one for the fuel solenoid.

Very interesting... I found the one that cut power to everything when I disconnected it, but did not see another. I'll look for the other today but I feel strongly that this is the source of the problem. Still waiting to test it in a few days and see if that loose relay connection had any effect.
If I do find another relay and it is the same, I can swap them and see what happens.