L2550 Electrical Issue - Ignition & Starting

[jaydavid]

Over several days, my L2550 was dying. First, tractor started perfectly and ran like a champ, but turning off the ignition and removing the key had on affect. Had to use the fuel shutoff to kill it. Next day, Hesitated, no idiot lights on first couple of attempts, stomped clutch, shifted to neutral, etc, started up but again would not turn off or restart. left setting for a day and then magically started but again would not shut off and then was dead for good. suspected the ignition switch so replaced; no help. have checked all fuses; clutch safety switch; fusable link at starter; cleaned cables (all 4 ends); and still dead. Flasher lights work but no idiot lights. battery at 12.5 volts and jumping doesn't help. multiple jiggling pushing/ pulling fuel shutoff has no affect. checking for power at ignition cable connection is negative (should have done this before buying new ignition). have 12.5 volts at starter. have checked all wiring for naked wires (found a nest on top of fuel tank and mouse chewed insulation from wire to tank, but it was ground wire. disconnected, cleaned, taped). checked all cable connectors that i culd find (have access panels laying all over garage). suggestions please.

 

[Stubbyie]

Simple first.

Go back over battery ground connections---shiny clean both ends.

Be certain battery is connected as should be (cables switched?).

Check wire at ignition switch you say is 'negative', meaning no power, and trace for possible fault. If hidden, use long jumper with good tight connections both ends.

You also indicate jumping no benefit and shows 12.5-vdc at starter. Check while jumping or put booster on battery--should show closer to 13.8- to 14-vdc. Might bad battery showing voltage but having no amperage.

Would not turn off indicates bad wire to fuel shutoff solenoid assuming you have one.

With known varmit problem (found nest) I'd start thinking wiring harness has more than one fault.

Double-check fuses with meter not visually.

Try test start by jumping across starter terminal(s).

Don't forget to locate and confirm all safety switches functional. May be the culprit and perhaps easiest. Clutch, PTO, seat, perhaps others.

Electrical problems can be time consuming and elusive. Sounds like you're on the right track just continue stepwise.

Please post results and how resolved so we may all learn.

 

[jaydavid]

simple first. did that. then did 100 other things and nothing worked.

then went back to simple first, rechecked all connections and one that appeared good had actually come apart inside the connector. since these were all securely bound into a tight bundle, it probably came from factory like this and eventually "burned" to the point it no longer touched. which probably explains the on again/ off again problem.

the culprit was a double wire connector that went to the looped/ inline fused link.

i still don't understand how the machine runs with the ignition disconnected but doesnt' matter at this point.

now all i have to do is redo all the trouble shooting to repair the flashers which worked until i repaired things. hate it.

thanks for the help.

 

[Russell King]

i still don't understand how the machine runs with the ignition disconnected but doesnt' matter at this point.

I am confused to your reference to ignition.

There is not really ignition on a diesel (no spark plugs, no coil) so it will run with the key turned off untill the fuel injection is stopped. The newer tractors shut the fuel off through the key and a solenoid.

See the information at this link
http://www.flashoffroad.com/Diesel/ForcedShutdown/shutdown.htm

 

[jaydavid]

Russell, exactly. When my tractor is working "normally" i simply turn the key to the off position, the solenoid fuel cutoff is deenergized and it shuts off. when i had the broken wire to the inline fused link, i could start the tractor by jumping across the starter, even when i had the "key switch" disconnected. I could the kill it by pulling the fuel shut off lever.

It's not a problem. The tractor is running great now. I just couldn't work it out in my head how the fuel shutoff was being energizer without the key switch being in the on position. sorry for using the word ignition.

thanks for the help.