L3600 electrical problem

[JimS]

Had my tractor out in the morning and started it several times. No problem. Went to start it later and just got a very brief noise. Sounded sort of like a bad connection arcing. Now nothing on the instrument panel - no lights, no clicking, nothing. Checked shift levers, etc but I don't think a safety switch would kill everything... I get a faint buzz when I turn on the hazard flasher switch. I checked the battery - it is fine (and replaced a few months ago). Checked the posts and cables - nice and tight. Checked the main fuse in the cable (something like 60A) - good. I checked power at the fuse marked "pannel" and got 12.5 V so it looks good. I am thinking maybe a relay went out? I don't have the wiring diagram so I am at a loss for what to check without tracing everything out. I found about 4 relays behind the instruments but have no idea what they are for. Considered switching places with them if they are the same number. If that was the problem it should change what happens at least a little.

Any suggestions?

 

[slan]

Did you check your grounding point for tightness or corrosion?
Follow your negative cable back to either the frame or ??
Sounds like a bad main connection.

 

[JimS]

Ground connection looks good and tests good. Relays are different types so no chance to swap. Really need a wiring diagram. Looks like I will have to buy the shop manual.

 

[rbargeron]

Jim - On my L3600 there was a 40-amp slow-blow fuse near the starter - it can look ok but be burned off inside at the end. Suggest checking it for continuity. Older models had a fusible link there. If it's bad it takes everything out like you describe. (34670-34530 Description FUSE, SLOW BLOW (40AMP) $3.31) On my rig there was a red wire chafing against a metal bracket near the main switch - it was enough of a short to burn one end of the fuse. Made that pop snap sound of a short. As always, prompt cheerful refund if info is bogus. Take care, DickB

 

[JimS]

Slan had it right. It was a bad connection between the ground cable on the battery at the frame connection. It was tight and conducted under low current (voltmeter or small test light) but would open with a bit more current (wouldn't light the instrument lights). So when I checked for power with the light/meter it looked good. There was enough rust and oxide on the connection that it was partially open even though it was mechanically tight.

Thanks.