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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 26287
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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The wire harness on my LT 160 caught fire because it was too

Customer Question

The wire harness on my LT 160 caught fire because it was too close to the engine block. ( I was cleaning out dry grass and dirt that was causing vapor lock and inadvertently moved the harness.) The insulation on the wire burned and caused the engine to stop running. I replaced the harness but nothing happens when I turn the key.
What is the next most likely source of the problem?
Submitted: 1 year ago.
Category: Small Engine
Expert:  Curtis B. replied 1 year ago.
Welcome to JUST ANSWER small engines, let me try to help you !! Is the fuse good? Single fuse for the ignition system. Do you have battery voltage to the key switch? Do you hear the fuel solenoid click when key is turned on? Of not, check power from fuse. Fuse gets power from the stater solenoids positive post. Do you have voltmeter or test light to follow the voltage? Is battery voltage above 12. 5 volts?
Customer: replied 1 year ago.
No solenoid click when key is turned. Just ab-so-lute-ly nothing. A fuse sounds likely, given the fact that there was sparking from the wires as the insulation burned off. I do not have a voltmeter but know someone who does.I have not checked voltage to the key switch.Do you know where the fuse is located on this model? (There is a loop in the new wire harness that looks like it might have a fuse in it, and I would assume that the new harness has a new fuse.)
Expert:  Curtis B. replied 1 year ago.
Parts list does not show a fuse! But the typical fuse is in the small red wire, that comes off the positive post of the starter solenoid. All that parts list shows is a fusible link, that is on ground wire and is part of the new harness.
Customer: replied 1 year ago.
The wire from starter solenoid is blue and "disappears" into the harness. (Solenoid is on the right, fusible link on the left of the machine.)So, my best bet is to get my friend with the voltage tester to come over and start at the ignition switch?
Expert:  Curtis B. replied 1 year ago.
Start at the starter solenoid, you do have the positive battery cable and the keyswitch power wire on the same terminal?
Customer: replied 1 year ago.
Yes, both on the same terminal. Unless I got it wrong, that's how it was before the fire.
Expert:  Curtis B. replied 1 year ago.
That is where all things start, with battery voltage. Cheap digital voltmeter less than $10.00 at retail or auto supply!
Customer: replied 1 year ago.
Could the starter solenoid have been fried by the shorting wires? What about those three small boxes on the frame? Wandering around the wiring system with a voltmeter by myself seems a fools errand, even is it only costs me $10!
Expert:  Curtis B. replied 1 year ago.
The three boxes are relays, and they could be damaged. Starter solenoid should be ok. Cam you jump across the starter solenoid to see if the engine will spin? This is quick test of the battery, cables and starter.
Customer: replied 1 year ago.
Any testing will have to wait until tomorrow (weather permitting). Since the machine was running fine before the harness burned and since the solenoid should be OK, my guess is that jumping the solenoid will show the battery and cables and starter are good.Do you have a best guess on the relays? (My thinking is that the "first in line" so to speak got fried by the shorting wires and protected the other two when it burned out.)
Expert:  Curtis B. replied 1 year ago.
One is for pto, one is for lights , not sure what the third one is for. Says dynamic brake? But all are the same number. Mark them and their plug in. , then you could swap one for another. To see if you get power. Are you sure battery is not completely dead?
Customer: replied 1 year ago.
I fully charged the battery while I was cleaning the outside of the engine block to fix the vapor lock problem. It cranked strongly when the machine started and has been sitting for only a week while I waited for delivery of the new wire harness.But now that you mention lights, those don't work either.
Expert:  Curtis B. replied 1 year ago.
?? Just a thought. Battery connections bad?
Customer: replied 1 year ago.
They look clean, but I did not sand them off this year. I took the battery out to replace the harness, and keep in mind that they were fine before the fire, so I would be really, really surprised if that was the problem.It is beginning to sound to me like the relay. Maybe I'll get one from the local John Deere dealer and swap that through the system to see if I can it to start.The "dynamic brake" probably refers to the fact that you have to press the forward or reverse pedal to get the machine to move.
Expert:  Curtis B. replied 1 year ago.
I don't think the relays have anything to do with start or voltage to the keyswitch! Let me know. Thanks.
Customer: replied 1 year ago.
There is a safety that you have to engage in order to start the engine. If you don't press that pedal nothing happens. My guess is that the relay for the dynamic brake is part of that safety and only allows power to the keyswitch when it is engaged. A damaged relay acts like a non-engaged safety.No lights seems to suggest the light relay was damaged, since lights only has a separate position on the keyswitch. If the light relay is damaged, the dynamic brake relay might also be damaged.Sound reasonable?
Expert:  Curtis B. replied 1 year ago.
That would keep starter from engaging, but does not kill circuit to key switch. Keyswitch would turn on and the fuel solenoid should click when the key is turned on.
Customer: replied 1 year ago.
I will jump the starter tomorrow and let you know. If I am right and the battery, cables and starter prove good from this test, it seems my only option is to get someone who knows what to test with a voltmeter to test the keyswitch.
Expert:  Curtis B. replied 1 year ago.
OK, let me know, thanks.