John Deere 4100 electrical/no start issue

[mike48130]

Looking at the schematic in the post below, it looks like the fusible link is before the switch, and powers several circuits. You could probably start pulling relays and connectors on these other circuits to see if one is having a high load. The post talks about voltage regulator issue, so maybe you have a similar issue.

http://www.tractorbynet.com/forums/...33021-jd-4100-voltage-regulator-meltdown.html

 

[Rdmmo]

Just getting back to messing with this 4100 no start issue. Pulled starter and had it checked. Operated fine during load test etc. I can’t find a short anywhere. Only wire that gets hot to the touch is the fusible link and then it pops after the motor turns over 4-5 Times. Loosened alternator so no binding there. water pump doesn’t seem to be bound up.

 

[Rdmmo]

I disconnected the glow plug relay and no difference. I will have to try and locate the K3 relay. No manual etc. Thanks.

 

[beenthere]

Rd
Here is screen shot of location that may help.

 

[Rdmmo]

Thanks for posting. Very helpful! I disconnected K2 and K3 with no change

Coincidentally, before I disconnected the relays I tried to start it and the ole 4100 started right up and ran like a dream. Fusible link wire was ice cold and never got hot at all the while it ran. Regrettably I shut it off and haven’t been able to duplicate it. Now when I try to start it, even with the relays unplugged, that fusible link wire gets red hot as it has been......

 

[Zebrafive]

I would disconnect the wire from the key to the starter. If the fusible link still blows, it's not the starter.

 

[Rdmmo]

I also disconnected the voltage regulator and tried it and that made no difference either

 

[Rdmmo]

I had previously taken the starter off and took it in to the auto parts store and had it load tested and it operated perfectly fine. Ran it numerous times. I also changed the key switch to a spare one that I have and that made no difference.

 

[Rdmmo]

I unplugged just about everything with no changes. I ordered a starter. Thinking I’ve got something weird going on with it even though it tested ok awhile back. It’s not turning over like it was. I’m hoping that’s it

 

[Rdmmo]

That’s what I was determined it was as well but I can’t find anything anywhere. I’ll continue to look. I checked all wiiring disconnected, cleaned and retightened all ground connections on the frame that I could find. I’ll carefully double check the positive cable again. Thanks