2002 rancher 350 es shift issue/blowing 30amp motor fuse..

[Suzdrtbk 0]

Recently acquired an 02' trx350 rancher es..bike is clean and low miles/hours..prior owner installed a bypass on it because he believed the ecu got wet or damaged and didn't want to fork the coin out for a new ecu..long story short..I ordered a new oem Honda ecu installed it and took off the bypass..bike runs but won't shift..it is currently blowing a 30amp motor fuse instantly when turning the key on..I've double checked the identical plug ins up-front and made sure they're in the correct harnesses..I've replaced the rectifier/regulator Recently still same issue..any help would be appreciated..

[jeepwm69 6,618]

Welcome aboard.

 

So before you removed the bypass was it shifting ok and blowing the fuse?

[Suzdrtbk 0]

Before removing the bypass the bike would shift fine every once in awhile..before I took the bypass off and got a new ecu it never blew fuses..the bike would jerk hard when you shifted it probably because it's bypassing the Rev limiter and safety stuff..it would have issues going into reverse and finding neutral and down shifting..

[jeepwm69 6,618]

Well I fixed my kid's 350 ES by converting it to a footshift.

 

The two ES fixers aren't on here a lot this time of year, but maybe one of them will chime in.

 

Looks like the first problem you need to find is the dead short that's blowing your fuse.  My guess is the wiring for the bypass required changing something that needs to be changed back. 

@retro

@Melatv

[Suzdrtbk 0]

I wouldn't mind footshift..but I just dropped quite a bit of coin for a new oem honda ecu and rectifer/regulator..im not big on electrical stuff haven't found any grounding wires or anything obvious but I'm definitely clueless now..

[jeepwm69 6,618]

17 minutes ago, Suzdrtbk said:

I wouldn't mind footshift..but I just dropped quite a bit of coin for a new oem honda ecu and rectifer/regulator..im not big on electrical stuff haven't found any grounding wires or anything obvious but I'm definitely clueless now..

 

What all was involved with removing the bypass setup?  If it wasn't blowing fuses before you did that then it would be reasonable to assume that something you un-did is causing the fuse to blow now.

[Suzdrtbk 0]

This is the link as to what it takes to install the kit..so just reverse the steps obviously..https://hondaesshiftkit.com/products/00-06-rancher-350-es/

[shadetree 5,468]

try unplugging the carb heater, see if the fuse still blows ?.

[Suzdrtbk 0]

I haven't tried that yet..what would the carb heater have anything to do with that?

[AKATV 691]

Get you some 30 amp fuses and start unplugging things one at a time till they stop blowing -lol

If your handy with a multi meter you should be able to narrow it down pretty quick

Do you have the wiring diagram/service manual?

if not you can download it here:

https://drive.google.com/drive/folders/1VocUaF1K4_fDh_SVCaq3Rkc747M58ZQd

Let us know what you find out-

[Suzdrtbk 0]

Yeah I've started doing that process of elimination..I have the service manual I just don't know why it's blowing that electric motor fuse after unistalling the bypass it wasn't blowing that fuse before..could it be a bad new ecu?

[AKATV 691]

I would say no, not likely but its possible

I would start by narrowing down the short

I would get that new ecu out of there too, use the old one in case things go south

It was doing the same thing with the old ECU correct?

Edited January 21, 2022 by AKATV

[Suzdrtbk 0]

It was not blowing this fuse with the old ecu plugged in with the bypass on it..im going to pull the new ecu and put old back in and change the fuse and see if anything changes..

[Fishfiles 17,154]

Fuses are getting expensive , so instead of wasting a slew of them , if you have a voltage / OHM meter , connect the leads to the fuse box where the fuse that is blowing goes and you can see and or even hear , if your meter is capable of sound , when the circuit has been disconnected ---- have also done the same thing witha 12 volt test light , by attaching the clamp to the positive post and the probe to the fuse holder wire that goes to the circuit , not the side of the fuse  that brings voltage to the fuse  

[retro 3,760]

Hi @Suzdrtbk, I can help you. The 30 amp Motor fuse that is blowing provides power to the shift motor circuit only, so your issue should be pretty easy to diagnose. Since there is a dead short somewhere causing the motor fuse to blow, using a multimeter to test the circuit is the safest way to proceed. We don't want to risk frying stuff or waste any more fuses...

 

Do you have a multimeter handy?

Have you taken the front fender off?

Where were the power supply wires for the shift kit connected when you got the Rancher? The accessory harness? Ignition switch? Or other? Which wire (colors) were the positive power wire connected to that provided power to the shift bypass kit that was removed? Was the negative power supply wire for the shift bypass kit connected to a frame ground, or to a green wire?

[Suzdrtbk 0]

The quad is actually at a buddies house..hes stumped tried checking everything you mentioned..Im not.sure what to do the quad won't shift now so not sure how to move it to take it somewhere else to get it checked out..