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.
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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
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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?
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