Alright, so my 2004 sportsman 500ho has been suffering from intermittent electronic issues. I am hoping that you guys could help point me in the right direction to get these cleared up.

First, ever since the day I bought my quad (used), the cooling fan always runs whenever the key is in the on position. I'm not too sure if this is proper but it is the least of my worries at this point...

Second, I am a victim of the slight pain-in-the *** created by electronic 4x4. Sometimes it works, sometimes it doesn't.

Third, my speedometer/ odometer doesn't work worth a damn. I checked the hall effect sensor and it seems good. I'm just getting no power to the unit at all.

Fourth, my lights go on strike after being used for more then 5 minutes. I remember discovering this issue while travelling roughly 30 mph through a tight, twisty, forest trail, in pitch black, by my self. Can you say SKETCHY!



But worst of all I think that my- well I don't know what it is that's wrong this time! The quad starts one day, doesn't even queue the electric fan the next. Bare with me as I spit-ball a few ideas:
Now I think the first 3 issues are un-related but the 4th may just be a clue to what is happening here...
The battery can take a charge, but I wonder if the stator isn't working properly?
For the last month or two the starter would drag after turning the key to the start position.. It would go CLICK (no noise for 2-3 seconds) then start turning over

I am probably going to try out a new battery pretty soon, but I am hoping to diagnose the exact problem first instead of just throwing money in it's rough direction. I have and will continue to search this and other forums to try and get to the bottom of this. But I appreciate and welcome any and all ideas or suggestions that you may have!


Thanks for your time

 

If you haven't had this done,or even if you have the replacement can go out also.The ecm module takes the place of the reg/rectifier. Controls charging,fan operation and has several circuit breakers inside and can cause all sorts of problems.If you're the original owner you should have gotten a recall notice on the ecm module.Huge ATV Recall by Polaris - Sportsman and Scrambler

 

if it's not the ecm(it really could be as it effects a lot of the bike) check to see it someone has hooked the fan to run all the time as you bought it used. depending on the hrs/miles on the bike it could use a fluid change in the awd system. it might help with the on/off again awd. just a thought.

 

Your first and fourth items are probably ecm related. Second and third have to work together. If the speedo doesn't work,the awd won't work either or will be intermittent. You can do the bypass at the speedo harness that some have done(tie the brown/white wire to a brown wire) to bypass the speedo and the awd should work. Or you can try this as sometimes it's a simple grounding problem.

 

ECM sounds like a good idea, I can get one for cheap so I'll start there.

I was out working on the sportsman this evening and came across this:



From what I can tell, it looks like the P.O. grounded all of the brown wires already. Is the awd fluid just the front diff fluid? I'll look into changing that over in the near future.

Now the speedo has always bugged me, I would like to just get a new oem/ aftermarket unit but I can't seem to find one at a decent price, any suggestions?

 

The coil mount is the common grounding point for all the ground wires from the factory. The video just showed splicing into the ground wires from the hub coils and regrounding to this point to make a positive ground if grounding is the issue and not a speedo problem. The problem on the after market speedos is that the harness wont work as the oem speedo internally completes completes the circuit on the brown/white awd wire. You'd still have to jump this wire to a brown or a good frame ground to complete the circuit or bite the bullet and buy a $300 speedo and solve this problem. Depending on your model there are "TWO" types of awd systems on the 2004 Sportsman 500! Hub activated and centralized(awd components in the front diff) which has it's own set of problems with plastic roll cage cracking that can affect awd operation. You haven't said which one you have! One just has a regulator/rectifier,the other(centralized awd) has the ecm module!!Plus here's a cheap 5 buck pdf service manual that can help if you don't have one,plus can tell you which oils to use.http://polaris-atv.brssm.com/2004-Po...ce-Manual.html

 

Oh, so that is actually the factory wiring then?

Im not exactly sure of my awd type, I can go find the serial number later tonight. But if it makes a difference i have the speedo with the gear indicator below the dial, not in the centre of it.

 

Yes this is the factory wiring. Look at the front differential. If it has wires going to it,it's a centralized awd system. If wires lead down each wheel side,you have a hub activated awd system.

 

Even easier way to tell is the twin locking hubs system has larger protruding front hubs and the newer single locking diff has hubs that look like the back hubs.

Dual locking hubs


Single locking front diff.

 

Looks like i have the hub activated awd system:

Theres wires going down to both hubs, plus i have the large hubs like the first picture

Also do those wires coming from the fan look factory? Maybe thats why it never shuts off..