Polaris ATV Forum banner

Failed key switch, melted grund wire - Again!

15K views 11 replies 5 participants last post by  stave7119 
#1 ·
Ok, so this is the second time this has happened! 2004.5 Sportsman 600 Twin. The first time was just over 2 years and 60hrs ago. Parked and shut the machine off for lunch and white smoke came out under the hood. No power to anything. Got it home and found that the key switch had shorted from the v-reg wire to the brown ground wire. Melted the ground wire all the way to the connector under the hood. Replaced the ground wire and switch ($85 from Polaris), tested everything I could think of and moved on.

Fast forward to last weekend in the middle of the trail. Key switch started acting up. It would start but as soon as I let off the switch it would stall. If I held the switch between run and start if would stay running and after a while I could let go and ride the machine. Until it stopped on the trail and I got a puff of smoke from the headlight pod. No power to anything. Pulled the pod and found the ground wire melted again. Towed out and home. Same issue. Switch is shorted and the brown wire melted.

I have included photos of the switch. I cut the part around the plug off the switch for the photos. I really don't want to go through this again. I plugged in a new switch and I have power. Once I get the ground wire replaced I will fire it up and test the charging system. Any suggestions would be helpful!
 

Attachments

See less See more
2
#2 · (Edited)
Steve, just wondering why that switch needs a ground wire? Doesn't the ignition just control the positive side of things? I could see if it had 2 ground wires (one in one out) just don't know why the ignition switch opens a ground circuit? Switch mounts into the plastic pod hole and no way does that switch have any connection to ground through the mount? Have you looked at the wire diagram for ur bike, and does it have that ground wire listed? Did a PO maybe install it and it don't belong there?
 
#3 · (Edited)
#4 ·
Thanks Jerry! The ground as far as I can tell is for the ETC in the throttle housing. None of the threads I have found say why it failed. They just indicate a failure of the key switch. Most have wired around the key switch or replaced it. Not sure if I am missing something that causes this or not. The first time was about 100 hrs after I got it. This time was 62hrs after the last time. Almost 1000 miles though.
 
#5 ·
I seen one post referencing the fuel gauge? Does that ground wire work the fuel gauge circuit?
 
#6 ·
Suggestion... when replacing that burned ground wire either fuse it or go around the ignition switch and go direct to the throttle housing?
 
#7 ·
Steve I'm not completely familiar with your model so help me understand. If I'm reading correctly there is a pos+ 12vdc wire coming directly from the VR to the key switch?
 
#8 ·
I have to look more closely at the wiring diagram. The wire does come from or go to the V reg. Not sure which way current goes though. Took a quick look at the diagram before I came inside. I will have to look at it more closely tomorrow. There are actually 2 wires in that pin connection at the switch but I don't remember where the other one comes from either.
 
#9 ·
Stave, I have 3 wiring diagrams for 04 600/700 Sportsman's; built before 2/20/03, after 2/20/03 and late models with fuel gauge - all are the same in respect to the red and brown wires.

The red wire goes from the battery to the Vreg, from the Vreg to the accessory plug in the headlight pod, from the acc plug to the key switch - the brown wire from the acc plug goes to frame ground and the key switch.

I would suspect a defect in the acc plug causing the problem or a faulty main switch design
 
#10 ·
Mine is the later one with the fuel gauge. Since I haven't been able to find any reason for the failure I thing it is the main switch design. This time I ordered a repair kit that includes the new switch and a pigtail wire harness with a new plug. I also got an extra switch. I think I will put a fuse in the ground wire so if it does happen again, all I will have to do is replace the switch and a fuse instead of a whole wire. A repair that could be done on the trail if needed.
 
  • Like
Reactions: FPD218
#11 ·
I've had to replaced multiple (3-4) key switches. Couple times I think it was because I used a cheap replacement instead of OEM.
But the switch(es) failing where just a symptom of the real cause: Bad voltage regulators.
I've found that when they fail, they can put out 18 volts or more, and this problem burns out the key switch.

Does your 600 have a diagnostic mode (turn key with transmission in neutral holding the reverse override button)? Then use override button to scroll through menu. You'll be able to see system voltage before starting and after started. Shouldn't be much more than 14 volts when running. Otherwise use a volt meter on battery when running.
 
#12 ·
Thanks for the reply. The first time it happened the regulator and/or charging system was the first thing I thought of. I tested everything trying to find an answer with negative results. Both of the failures (1000 miles and 62hrs apart) happened with the expensive OEM switches. As soon as I plug in a new switch, it is back up and running. So this time I put a fuse in the ground wire so if it does short, it will blow the fuse and save the wire. Then all I have to do is plug in a new fuse and key switch to get back up and running.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top