2017 Sportsman 570 EPS - Starts irratically

[jung4g]

 The quad has done this off and on, almost since new, but it's gotten worse this year. Sometimes if I freshly charge the battery, it'll work fine, others times that won't matter. Turning the key to on it sounds like it's connecting as I go to the start position, slightly before the full turn, but it's not like there is just a sweet spot to find, it's totally erratic.

Now the battery is basically dead so I put a new, slightly bigger AGM battery in today to replace the factory one with all of 800 miles on it, but those have lots of plowing hours included. 

I was able to get it started once, but it still went into limp mode after just a few moments of driving it (that's another topic), so I put it back in the garage and started probing around. Now it doesn't even try to turn over.

Is an ignition switch, the $18 shipped aftermarket variety on Amazon worth a shot? Or should I go straight for the starter? The new switch may not come for over a week, so I hate to just put my hopes in that if I'm missing something obvious. Fuses are good, so it's not something super obvious.

[Admin]

Does the starter solenoid click? Have you tried jumping the solenoid or starter directly?

[jung4g]

Yeah, it does click and usually it'll turn over. I ordered a new spark plug, solenoid, and ignition switch last night since the aftermarket parts are cheap and I can have them by the weekend to test. 

I pulled a few things apart last night, including the whole front cover, and plan to undo a bunch of the wiring clean terminals and reassemble when I get the new parts. I'm also planning to run supplemental grounds and postives from the battery to frame like I would do for car stereo installs to help maximize the potential of the electrical system. Electrical seems to be the overall issue whenever I've run into intermittent issues.

Maybe that'll also help some diagcodes that recently popped up as well.

[jung4g]

Quick update on this in case it helps anyone... After removing the wiring on the terminal block, taking a stainless brush to them, and redoing that setup nice and snug, I was able to get the machine running right away.

However, driving up from the frozen pond with it a bit later, it shut off on me, due to the fact I was driving on the old ignition switch as the new one arrived later yesterday. I was able to wiggle the wires around and get it home, but after putting the new switch in and finding that it was still intermittent, and pull the ignition switch plug apart and removed all of the wire terminals from it. I cleaned the dielectric off those with an air hose, scrubbed them the bit I could, and then carefully bent the inner portion that acts like a spring to maximize the connection as some were a big saggy. Note that I had that apart a few weeks ago as I found one of those wires had broken nearly through due to a bit of oxidation at the terminal (see the pic). I soldered and crimped it back it place and it was holding well. A small screwdriver or a terminal disassembly tool (like I use) made pulling the wires out very simple.

Now it's working beautifully. Strongs stronger than it ever has. I'm 99% sure the worn terminals that I bent back and the broken wire were causing all of my starting issues after all of that.

I'll keep the old ignition switch and starter solenoid I'd bought as backups.

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