I’ve got an 07 rancher 420 4x4 manual shift that is driving me bananas with a wiring issue. Recently bought it after it sat for about 3 years in a shed after being flipped. Been through all the wiring and motor checking everything and am at a loss. It will only start in gear with the front brake pulled in. In neutral it does not have a neutral light and doesn’t supply ground to injector when cranking but will when in gear and holding brake. I’ve changed out the gear position switch/sensor and no change. Here’s where it gets interesting. With the key off, testing the green wire with red stipe (neutral) on the gear position sensor harness, I have continuity to ground. Once the key is turned on it does not have ground, thus no neutral light. I have changed out key switch with new OEM, been all over the wire harness and connectors, only thing I can think is PGM at this point. Any one ever seen this?

 

Can't say I have had that fault on a 420. They have horrendously over-complex wiring and the self diagnosis system rarely shows the fault. However, are you getting a flashing code on either EFI warning light or gear indicator? A common problem with old 420s is a relay in the battery box going faulty, that short bit of loom between relays and the big grey connector also gives trouble if the battery box has been full of crud, courtesy of that nice plastic scoop Honda put in the box lid, so animal feed, grain, bits of dead deer, etc, that fall off the rear rack, will side into the battery box.

 

It has the non digital dash so only lights and nothing lights up. I spent a whole day going through all the wiring after removing every bit of tape and only issue I found was in the front. The wiring coming from the dash and headlight/kill switch was very corroded at the plug behind the radiator. The wiring itself had even turned black. I cut all the wires back til I found good wiring and then wired in a new connector with enough wire to replace the bad. I am even getting good continuity from every wire all the way to the Pgm. Going over it once more I did find something interesting last night. The lg/r neutral wire loops into a one way diode with a lg/b wire coming out. It has no continuity one way and has a resistance of 565 the other way. If I’m not mistaken there should be no resistance one way and an open loop the other way.

 

Yes, resistance in the diode seems odd. That switch unit on the LH handlebar is one we sometimes replace, electric switch buttons (on ES models) are in it, and go bad, also the starter button can become faulty, sometimes you can take the switch to pieces but it is easier to just replace the unit.

 

Got an update for anyone else having this problem. There was a ground wire and one of the Pgm connectors that came loose inside the connector and when plugging it in, it back out inside the connector just enough to not make a connection and not be noticeable. Once pushed in, everything started working correctly. Hope this helps others