2004 AC 400 4x4 FIS Problem
 

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'

2004 AC 400 4x4 FIS Problem
 

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

2004 AC 400 4x4 FIS Problem
 

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.

2004 AC 400 4x4 FIS Problem
 

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

2004 AC 400 4x4 FIS Problem
 

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

2004 AC 400 4x4 FIS Problem
 

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

2004 AC 400 4x4 FIS Problem
 

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]

https://i499.photobucket.com/albums/...ng_diagram.jpg

2004 AC 400 4x4 FIS Problem
 

My WAG (Wild Ass 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.

2004 AC 400 4x4 FIS Problem
 

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

2004 AC 400 4x4 FIS Problem
 

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.

2004 AC 400 4x4 FIS Problem
 

Kurtl,

I have been scratching my head trying to help you out and and I am stumped on one thing. I am pretty sure your CAT does not have a temperature shutoff. (for example a switch/sensor that shuts the engine off when it gets too hot) I am pretty sure the engine would continue to run and heat up until the engine seized up. Now the engines I have seen do this "may" restart after cooling off but the engine then sounds like a diesel with a ton of rattling.

I even looked at the witing diagram and cannot fing such a sensor. I think some small engines have a low oil shut off but I can't find that on your machine either. So this has me leaning towards an electrical issue with either the Coil, Regulator/Rectifier or the CDI.

I had an old quad that after running for a little while the CDI would heat up and quit working. This was discovered because there is a test for the CDI and I ran the machine until the problem occured and removed the CDI and performed the test and found it was faulty. I replaced it (about $350) and everything was fine.

Also, as HeftyLefty suggested I have read about a bad Regulator rectifier causing some issues as well. If you have someone close that you know with the same machine you might try switching parts (assuming theirs works) and try it. OR use the service manual and perform the test procedures.

On a side note I am pretty sure your AC should run HOT. My 400 and 500 run so hot it can feels like my leg is about to burst into flames but my cooling fan rarely runs! Unless it is winter and about 10below outside.

Swampy

2004 AC 400 4x4 FIS Problem
 

It sounds like the cooling fan diode is broke.Its very common on this model and year.Its not the fan switch but the diode that goes bad,they are very poor design and arctic cat sells the updated one for your model.I had the same year and make in for the same problem and thats what is was.I will look up the part number at work tomorrow and message it to you.Its a super easy and cheap repair.I hope you havent bought a CDI unit or anything else expensive.Ill be in touch with the number and how to change it.

2004 AC 400 4x4 FIS Problem
 

I did some more experimenting this weekend, and heres what i came up with:

I bypassed all of the wiring with my own. I ran a positive wire from the battery, through a fuse, and straight to the fan connector. The negative wire went from the negative battery terminal, to the fan switch, and then to the fan connector.

I then started the engine and let it run until failure--the fan still did not come on. I was able to put a temperature probe on the radiator, i could fairly consistently determine when the engine would overheat (around ~185-190F at the radiator, and i assume this must be much different temperature than the oil passing over the fan switch). If i manually switched on the fan, the engine would run until i discontinued the fan.

I then replaced the switch with the new switch, same thing.

Also - when the engine 'overheats' the temperature light does not come on. The light comes in with the key on and the engine off, so i know the light works. Looking at the wiring diagram, the light should come on when the engine overheats. This sensor should trip around 300degrees, as opposed to the 240 on the fan switch.


My next tests will be to place the fan switch in oil and make sure the new one is within spec according to the service manual. My buddy also wants to try bypassing the fan by hooking up a relay, in case the coil is acting screwy and preventing the fan switch from functioning properly

--kurt

2004 AC 400 4x4 FIS Problem
 

<div class="FTQUOTE"><begin quote>Originally posted by: cbr600t

It sounds like the cooling fan diode is broke.Its very common on this model and year.Its not the fan switch but the diode that goes bad,they are very poor design and arctic cat sells the updated one for your model.I had the same year and make in for the same problem and thats what is was.I will look up the part number at work tomorrow and message it to you.Its a super easy and cheap repair.I hope you havent bought a CDI unit or anything else expensive.Ill be in touch with the number and how to change it.</end quote></div>

I am really interested where this diode is. If you read my previous post you'll see I have the same problem even with completely different wiring - did the new wiring bypass this diode or (i hope) is this diode somehow part of the fan assembly?

thanks--kurt

2004 AC 400 4x4 FIS Problem
 

Here's another update:

Today I tried hooking up a relay so that the fan had nothing to do with the circuit (thinking the coil was sending some strange signal back to the switch), and it still 'overheated'.

I then performed the little science experiment shown in the manual to make absolutely sure that the switch was working as intended. I placed some vegetable oil in a sauce pan, suspended the switch, and measured at what temperature it closed and reopened--this was very close to the manual, i.e. within spec.

So, in summary, I should have eliminated all of the factors out of the oil cooling system to no avail (my own wiring, new & tested switch, eliminated possibility of fan), this leads me to believe one of two things are true:

1) Something is killing the engine before it should be, not allowing the switch to get hot enough
2) The switch is somehow not being heated properly (oil blockage??)

Supporting #1, when the engine does 'overheat' the light does not come on as it should indicated by the wiring diagram.

I do not believe #2 to be true, because at one point i accidentally started the atv without the fan switch installed, and the oil was being pumped out very well [img]i/expressions/face-icon-small-smile.gif[/img]

So, I was hoping someone had any ideas on what exactly could be signaling the atv to shut down, The only way I see from the wiring diagram is the oil temperature switch, which according to the light and testing isn't/shouldn't be the cause. I strongly believe that the engine is in fact overheating--and my reasoning is in the above posts.

--kurt

2004 AC 400 4x4 FIS Problem
 

Kurt,

About 3 years ago my experience with my 2003 AC 400 taught me that there is no low-oil shutoff. I had water in with my oil (I won't go into how it got there) I was plowing in the winter at 20 below and the water froze in the cooling fins on the oil cooler. Which kept oil out of the oil sump. So not enough oil got to the top end and it took out the cam, head and cylinder. The only thing I noticed was the engine run REALLY HOT! Hotter than normal and before I could see what was the matter the cam seized and she stopped running.

So from my experience there is no electrical component ( diode, switch) that will shut this AC machine off if there is an oil blockage. It should continue to run right up until the engine seizes. If there is then mine malfunctioned and my AC technician was wrong. There is a temperature light but not a shutoff.

I also was recently brought a Honda Rancher to rebuild that the oil drain plug fell out of while it was being ridden at nearly top speed on a trail. Needless to say it went about 50 ft and 25 feet of that was leaving an oil trail and BAM! the engine totally seized up. No low oil shutoff there either. So I think you definitely have an electrical issue going on.

I would begin to test the CDI, Voltage Regulator, and or the Coil as well.

SJ

2004 AC 400 4x4 FIS Problem
 

on your ac if you jump the fan and go riding will it stay running cat has a problem with the wires coming off of the magneto and the stator down inside the casing the wires rub through and then you lose spark then after a while it will start back up i replaced the wires coming up and havent had a problem with mine since

2004 AC 400 4x4 FIS Problem
 

Newb,

After installing tracks on the beast I had similar problems with temp light coming on and fan not. The 400 works pretty hard to turn all that gear so I needed to know what was wrong and get it fixed right.
What ended up being the problem was a bad fan ground connection, or lack of in this case.

It seems Cat somehow attached a plastic ground stud to something and it broke off it's mounting location.
Because the machines run cool and rarely use the fan, when I found the wire covered in dirt hanging with what appeared to be a plug in it, I wrote it off as an assessory wire of some sort.

Wrong, It was the fan ground.
Hopefully in the process of checking every other posibility I have not blown a diode or overheated a thermo switch with a lighter etc and caused another problem.

Although my rig is carburated I'm pretty sure the temp light and fan switch are probably wired the same.
Simply put, at the bottom front right side of engine are two sensors. The inboard one is the temp light. The outboard is the fan switch. The two do not work together.

If you unplug the fan and put a jump wire across the plug terminals and turn the key on, the fan should run assuming nothing else is wrong.
If you unplug the light plug and jump it, the temp light will come on. Note: You actually need to start the rig for the light check to work because the ignition "on" position has a built in bulb check that won't turn off untill you start it.


It's well worth checking your own rig if in doubt. I was 8 miles from the truck in 2 feet of snow when mine came on and it was not a good feeling seeing snow boiling off as steam from my radiator trying to cool it off.

My bio has a picture of the stud and a link to a video of my ride in the snow.

Hope this save someone else the frustration of a simple problem.

2 days later: Decided full instrumentation was in order to monitor how the rig is running. Picture at my bio because I don't know how to put it in the message.

2004 AC 400 4x4 FIS Problem
 

is tehre a way to keep the fan on all the time?