Hello all,

I was hoping someone could help me out with my atv problem. I was riding it a month or two ago through the trails, went off-trail (riding slow) and it stalled out, it wouldn't start, not even turn over. So I sat for a few minutes and it started...okay i thought, let me start heading home. I get down through the slow trail and it stalled again. I let it sit then got moving again. I was able to keep it moving really quick through the rest of the trails all the way home, as soon as I slowed up--it stalled again. I was assuming the Oil Cooler radiator fan stopped working---and that my Cat was overheating. I then began troubleshooting--upon putting a 14v drill-battery to it, it spun right up---i then thought it might have been a fuse, which turned out okay---so i looked up the electrical diagram, and then figured it must be the cooling fan switch, So i ordered a new one ($140).

After replacing the switch, I let my 4wheeler idle for about 1/2 hour, the cooling fan did not come on, and it finally stalled out, not turning over until it seemingly cooled down. Unfortunately the place I ordered the part from doesn't accept returns of electrical parts (grrrr).

I then busted out my multi-meter and began metering, i finally put a lighter to the cooling fan switch (which screws into the engine block, sensing oil temperature) and it started then fan after a minute with the lighter.

So now I am really confused, I was hoping anyone could help me troubleshoot this problem, or -- what i really hope is that someone has enough arctic cat experience to say "oh this happens all the time...try doing this"

HELP! I need to get back on the trails before winter!

thanks--kurt


edit: more info: it runs excellent, starts on 1/2 crank, fresh gas, new battery this year...just dies out when it 'seemingly overheats'

 

Kurtl,

I had an issue similar to what you describe a long time ago with and old Suzuki quad I had. The thing would start and run fine when cold and when it warmed up it would just stop running. Mine would turn over with the electric start but that was it. You could also turn it over with the pull start until your arm fell off. Nothing would help until it cooled off. At which time it would start and run again for a little while until it warmed up again.

Mine ended up being an electrical issue in the CDI, which was frustrating to figure out. What I did was blow cool air from a compressor across the CDI box for a minute or so and it would start and run. I accidently discovered this because when trying to determine the problem I burnt the crap out of my hand on the CDI box trying to get at the coil (which is what I thought it was). I replaced the CDI and the rectifier on the charging system (which was a suggestion from a dealer to keep from frying the new CDI). Cost about $450 total.

I am not suggesting you replace your CDI because it is SPENDY! But there are a set of test procedures for the CDI, voltage regulator/rectifier and the coil in the AC service manual. I had it narrowed down to one of these three things on my old Suzuki with similar symptoms but had no test procedures and just started replacing components.

I do not have my service manual handy or I could give you the procedures to test them with your voltmeter. I will see if I can find the instructions for them if you do not have a service manual.

I would start by trying to determine if the engine will turn over with the pull rope when the problem occurs. If it turns over with the pull rope but still won't start this would narrow it down to an ignition electrical issue not overheating.

Once you know it is an electrical issue and not an overheating issue then you can begin going through and tracing wires and checking the ignition components and wires.

Hope this helps

SJ

 

go to your local Radioshack and get a can of Component Cooler# 64-4321. Spray it on the bottom of the CDI, if it cools in seconds and restarts, it's probably the CDI. You can test the coil the same way.

 

Swampyjunior,

I found in a thread 2 years ago you offered to send someone a wiring diagram and service manual for an 04 AC 400. I was wondering if you still had access to these.

Also, thanks for the info, I am hoping I can spend more time troubleshooting this weekend...while my buddies are all out riding [img]i/expressions/face-icon-small-sad.gif[/img]


--kurt

 

Kurt,

I believe I sent the wiring diagram but my service manual is a paper copy and I ran into trouble trying to scan just the parts for a 400. I did find a post here a little while ago where you could download a copy off the internet for your specific model.

I can send you the wiring diagram to get you started and I will look for the online manual and get back to you. Unless someone else on here has a better memory than I do. PM me and give me an email address to send the wiring diagram to.

I usually use the wiring diagram to tell me what the wires hook up to. I have found all of my shorts by tracing wires and looking for where they are rubbed. It is time consuming to remove the plastic and do. I now make it a habit to do this every winter as a maintenance project. I believe I have just over 12,000 miles on my AC 400 so I believe it is helping me to keep it running.

SJ

 

Okay, i've spent quite a bit more time on this and i still haven't solved the issue. I have the front end apart to allow easy access to wiring and I have since bought the official arctic cat service manual (which is very nice btw). According to the wiring diagrams, the oil cooler fan and switch is not related to the CDI (other than ground, of course). The fan gets positive power when the key is turned on, and ground runs through the switch, to the fan. The switch allows ground to pass through when it reaches a threshold temperature.

I can start the fan a number of ways. One way is to take out the sensor switch and place a lighter to it. Another way is connecting the two wires, bypassing the switch. I have also tested the resistance of the fan coil which is within spec according to the manual (<1ohm). Also note from my original post that I have tried replacing the fan switch.

Another shot in the dark i took was changing the oil and filter, hoping that the filter (which is part of the little channel that oil passes through and by the fan temp switch) was dirty and not allowing oil to pass through fast enough by the switch. However, after changing the oil & filter I let the atv run and it eventually overheated without the fan coming on.

I also tried something new this time, which was bypassing the switch after it overheated. After touching the two wires together, the fan remained on until it cooled down--which puzzles me. I was unable to re-start the four-wheeler until it cooled down...I also tried pull-starting it without success, It seems that something is cutting spark to avoid damage to the engine. Also note that it wouldn't start after the fan shut off, it still needed to cool down longer before I was able to start it again.

I still believe this is an overheating issue and not an electrical issue for three reasons:
1 - The fan does not come on while idling the atv for an extended amount of time (30-45 minutes). The fan used to come on 'generously' any time I was at a stand-still.
2 - The fact that I have to let the engine cool down after it shuts off, and after re-starting it, it takes a shorter time until it shuts down again.
3 - Now that it is colder out, it takes a noticable amount more of time until it cuts out.


So I have ruled out a faulty switch, and ruled out a faulty fan. I think i've also ruled out the CDI because it is not part of the circuit. I also believe I ruled out faulty wiring.....so now I am completely stumped! [img]i/expressions/face-icon-small-confused.gif[/img]

Any ideas/help/suggestions would be greatly appreciated!

-kurt

 

Here's the wiring diagram if anyone is interested. If you're really into helping me out and need a higher-resolution pdf, send me a pm [img]i/expressions/face-icon-small-smile.gif[/img]

 

My WAG (Wild *** Guess) is a faulty
sensor switch. Lets review evidence-1.You say the fan used to cycle on and off regularly, now it doesn't. 2. You can get the fan to come on using the sensor, IF you hold a LIVE FLAME to it for a minute. Hot oil is several HUNDRED degrees Fahrenheit, a live flame is 3000+ degrees Fahrenheit, and you have to apply it for a minute. There is too long a delay there.

You say you have a meter and the manual, measure the sensors resistance (in ohms), both open (off) and closed (on with fan running). I'd bet a box of doughnuts that the readings are out of spec. I bet you replace the sensor, and it will work right once again.

 

We're going to have to go out for some donuts - your treat [img]i/expressions/face-icon-small-smile.gif[/img]

I appreciate the input, but I have tried replacing the switch ($140 un-returnable part ugh!) to no avail. The engine still overheated without running the fan.

After talking with my buddy, I think the next step would be to run my own wiring directly from the battery, through the switch, and on to the fan, bypassing diodes, connectors and the key-switch. This is a cheap experiement to set up. I will also try it again replacing the switch. I would also want to check on the fan being the problem. Even though it is within spec, it is possible that there may be a dead spot in the coil, or something like that. I may first try it with a 12v computer fan, and then (if the computer fan works as expected), an actual replacement fan.

thanks again,

kurt

 

NO FAIR! LOL you didn't mention in your post that you had replaced the sensor switch!. Trace your fan switch (15) circuit and see if it goes thru #22, the regulator / rectifier. The regulator may pick up the pulse from the sensor, but isn't sending pulse or voltage necessary to kick the fan on.

Which would mean the regulator / rectifier has had a stroke and is partially dead.