Check the battery cables for corrosion up inside the insulation near the battery lugs - battery acid will wick up into the strands of copper and corrode the cable from within, causing it to become high resistance - and can cause the type of symptoms you have described.
You can try using an automobile jumper cable to bypass the battery cables - jump from battery positive to relay positive, then jump from battery negative to engine case... do either of these eliminate the problem? Then you have a bad cable.
'01 660 Raptor, Burgard +2+1 arms, YFZ Shocks, LSR anti-vibe, CTR pipe, jetted, K&N
'01 Polaris Scrambler 400, K&N
'02 Honda 400ex, Big Gun pipe, jetted, K&N, Lonestar +2 A-arms, Lonestar anti-vibe
'04 Suzuki LTZ400
'16 RZR XP4 1000 Turbo
Last edited by QuadManiac; 07-30-2019 at 03:07 PM.