Well, I bought this 2005 Sportsman 400 for $350. They stated a little kid pulled all of the wires out and it no longer had power. It also needed a belt. Anyways, I checked all of the wires. Brown / Black wire were broken and replaced for the starter solenoid.

The quad will turn over with power direct to starter but there are no lights with key on etc. I don't think this is related but they replaced the ignition with a button ignition for some reason. I know that the 2005 Sportsman 400s were all pretty much recalled for a bad ECM.

I spoke with a dealer that will replace the ECM for free but I was curious if there is anything else that I could be missing before I head over to the dealer and they try to charge me to fix everything else to see if their ECM is working properly.

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2005 Sportsman 400 Wiring Diagram, Repair Manual, Manual.
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I purchased the manual for the Sportsman online and it has all of the wiring schematics and diagrams which is really helpful. I am keywording this post so anyone that is googling can find it if they need it in the future. If this link goes down you should be able to email me at ron[at]redridge.co and I will send it over.

https://drive.google.com/file/d/0BwT...it?usp=sharing

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Thanks in advanced for any help!

 

Since you have the manual,the dealer will handle the ecm issue also,I'd just break down and get a complete wiring harness and wire it up yourself. 250 bucks for the harness rather than chasing all around what the previous owner has butchered up. You'll still be money ahead if the 400 is in decent enough shape.I've seen plenty of ones like you're describing. Item#8 Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

Sorry if this isn't the right practice for a follow-up/related question - my knowledge of forum etiquette is less than that of ATV repair. But I try

I have a 2005 Sportsman 400 as well. After a decent ride and trailer home last year, my ATV just quit all electric. The battery had come loose, so I assumed a broken wire or something. I checked those as best I could, but it doesn't seem to be the cause.

I connected booster cables and used a test light to see where power was 'stopping' - if I connect the positive cable and use the frame to test, there seems to be no ground. I tried connecting the ground to the ATVs ground cable, frame and the bolt where the two connect... is it really possible that I somehow lost ground??

To be clear - even with booster cables, I have NO juice. No instruments, nada.

 

In all probability it's the ecm module even if you had the recall done. If in doubt about a good ground,you can remove the frame ground wire,clean any paint around it along with checking continuity on the ground wire itself.Can't remember off hand,but check that you have a frame to engine ground strap on the top motor mount and that it hasn't broken.If you verify it's not a ground problem,the ecm contains the main circuit breakers along with the charging circuit,fan circuit,etc. If the circuit breaker has shorted out(like a lot were)then that would keep power from the rest of the machine.Some ecms would only have charging problems,others simply shorted out causing a complete loss of power to the atv,even the replacement US made ecms did the same thing on many of them.

 

OPT - ECM was replaced in the summer of 2012, it would stink if that's bad already/again. I will check the ground aspects and see if something is broken along the way before I get too stressed about the ECM. Is there any way to test the ECM other than the "everything else seems fine" method and taking it to the shop?

Will report back any findings of wire issues.

 

Well, I just connected booster cables to a known good battery. From there, I connected the positive booster cable to a test light and connected the negative booster cable to about 20 point on the ATV's chassis, ground cable, etc... and no light.

As soon as I touched the negative booster cable, the light is bright as can be (figured I'd add this just to cover the bases ).

So in my mind, this clearly means the machine is no longer grounded... so another bad ECM (after about 20 miles since it was replaced)??

 

From what I'm understanding you've done,jumper cables to a good battery,test light lead on + jumper end,tester point on different ground places along with - lead even on main ground cable and still no light? Only with test light touching both jumper leads it lights? Something still sounds strange..Better off jumping straight to the existing battery,then checking points around the machine if the lead is long enough,plus check for the engine to frame ground strap connection.Can't say 100 percent it's the ecm as long as you still may have a ground problem.Plus check directly at wire harness leading into the ecm.With a good battery,good grounds,key on,there should at least be one wire hot somewhere in this harness leading in to the ecm..

 

Hey guys, thanks for your help. Thought I should update this thread. We got all of the wires fixed, the dash still doesn't work but that doesn't bother me too much. Maybe later I will look at it again.

So we got the wires fixed and it would turn over but not start so I figured it was something electrical still. Took it to the dealer, had them check the VIN and it already had the ECM replaced. So I brought it home, took it all apart. Took old plug out and was going to replace it with a new but accidentally put the old one back in then put plastics over it lol.

Dumped a little gas in carb and it started right up. Needed to get the air out of the coolant system though. Right now the fan DOES NOT turn on. Ever really. It gets really hot and I can hear the coolant bubbling so I don't ride it too long before letting it rest. We did get the fan on once though. Don't remember what we did but we know the thermostat works, the pump works, etc.

The plastic is a little beat up and was missing every screw. About 50 zip ties later it is all good to go. I am buying a new bumper for the front regardless though and new tires.

 

You can always check the fan motor itself by applying 12 volts direct to the connector to see if it's operating properly. No sensor on the radiator on this model as the main fan trigger is still in the ecm module. There is a is a thermal sensor on the cylinder that you can check out to see if it is the problem on the fan also. Just check resistance on the wire to ground when cold,then when it warms up. The resistance should drop if it's ok.Plus not a bad idea to pull the radiator cap and let it idle to expel any trapped air,then top off the radiator and coolant bottle. No speedo display could prevent the awd from working as the ground goes through it from the awd switch. If you don't intend on replacing the high $ speedo(if it's faulty) and you don't have awd,you can just jump the brown/white (awd ground wire) in the speedo harness to a good ground(brown wire). Hopefully this will work on the centalized awd system.

 

I love you for that information. My AWD does not work. I didn't know why. It was on my list. I am going to check that now. Thanks a lot.