Can't find positive wiring harness from battery to starter

If your 2008 Polaris Trail Boss is not starting from the ignition switch but starts when you jump the solenoid, there are a few possible causes for this issue. Here are some troubleshooting steps you can follow:
1. Check the ignition switch: Even though you mentioned that you installed a new key switch, it's still worth verifying that the ignition switch is functioning correctly. Make sure it is properly connected and that the contacts inside the switch are not worn out or damaged.
2. Inspect the wiring: Examine the wiring harness connected to the ignition switch, solenoid, and starter. Look for any loose, corroded, or damaged wires that could be causing a poor connection or preventing the signal from reaching the solenoid when you turn the key to the "crank" position. Repair or replace any faulty wiring as necessary.
3. Test the solenoid: Even though you mentioned that the machine starts when you jump the solenoid, it's still worth testing the solenoid itself. Using a multimeter, check if the solenoid is receiving power when the key is turned to the "crank" position. If there is no power, the issue could be with the ignition switch, wiring, or a related component.
4. Verify the starter: Ensure that the starter motor is in good working condition. If the solenoid is receiving power, but the starter motor does not engage when you turn the key to the "crank" position, the starter motor itself may be faulty and need to be replaced.
5. Check the battery: A weak or discharged battery can also cause starting issues. Make sure the battery is fully charged and in good condition. Clean the battery terminals and ensure they are securely connected.
If you've followed these steps and are still experiencing difficulties, it may be helpful to consult a professional mechanic or a Polaris dealer who can diagnose and resolve the specific issue with your ATV.

Video below might help

Question edited for clarity.
Question moved from Misc to model category.

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Just close the chat box on the right.

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If the battery is good then most likely the starter again.

I have found with these Crown Vic's,especially police cars,they manage when the get in accidents to hit the right front of the cars and when they do they damage the wiring harness. The rain,salt,snow get in the harness and you eventually have problems. Look under the car in front of the right front tire and you'll see. Good size wiring harness. Look at it for damage,or sometimes you'll see like a light green dust coming out of the harness. Usually where I find my breaks,shorts or opens.

See if you have power at the solenoid wire when key is held in crank position. If you do, then battery connections are not tight, or you maybe got a defective starter or solenoid. If no power when key is held in cranking position, trace the start circuit backward from the starter solenoid to the ignition switch-starter relay and the neutral safety switch are in that path. Check for power in the start wire leaving the ignition switch, by backprobing with a voltmeter or testlight the ignition switch harness connector.

BEST TO BUY A HAYNES REPAIR MANUAL BECAUSE YOU NEED TO SEE HOW YOUR FUSE LINKS BATTERY SUPPLY WIRES HOOK TO STARTER SOLENOID AND ALTERNATOR.YOU NEED TO SEE YOUR TRANSMISSION NEUTRAL POSITION SWITCH WIRES SET UP TO STARTER.IF YOU GET WIRING WRONG.CAR WILL NOT CRANK.

If the switch (neutral safety switch) is broken, it will not crank regardless whether you jump the battery or a new battery is installed. I don't have specific manual for your year that's why my advice is as in general. With a remote starter tool, bypassing the solenoid wire with remote starter which is connected to the positive terminal of the battery of it's other end. Once positive current flows from the battery, through the remote switch, flowing towards the solenoid, the starter should engage indicating a bad wiring harness connection from ignition switch. If it doesn't crank at all you may have a bad starter assembly and needs replacing. If your starter is clicking using it's own battery power, your battery is low of charge or your charging system is malfunctioning.

Pls, rate this suggestion, thank you.

when it wont start, turn your headlights on, see if they work if they dont, find out why. When it wont start, take a wire from the positive battery terminal and touch it to the small post on the starter solenoid, it should crank. If it now cranks, theres a problem between the ign switch and the starter solenoid.

try lookin at the wiring harness under the battery tray,seen them corrode there alot

seems like the start wire is being fed by 12v --check the start wire for shorting to a hot wire ,maybe the at the starter harness connector.With the start wire disconnected check voltage at the start wire end--should have no voltage.Good-luck