RTV900 overheating, cooling fan off

   / RTV900 overheating, cooling fan off #1  

Uncle Doug

Gold Member
Joined
Oct 19, 2008
Messages
424
Location
Dayton, TX
Tractor
Kubota L3000
My 2006 RTV900 has started overheating after running for about 20 minutes. I noticed that the cooling fan is not coming on. Has anyone had this issue before. Is it most likely a fuse or a bad fan?

Any links to a wring diagram?
 
   / RTV900 overheating, cooling fan off #2  
stupid questions,is the both hoses warm? are you full of coolant? do you have a external cab heater and are both of the heater hoses warm? is it full of coolant?

now for the causes; belt on the water pump slipping,the coolant temp sensor bad,air bubble in the engine,fan switch not working.radiator fins blocked/tubes blocked,fan bad,thermostat stuck?

now to test the fan switch. it is the front one on the head,by the water outlet.take it off and ground it,it should turn the fan on,now the other one in the head,if you take that off and ground it it should bury the gauge to high.

to test the fan unplug the weather pack connector to the fan and put a 12v power and a ground to the fan,if it runs,youre ok,check the fuse in the fuse block,not 100% sure which fuse it is,but i think the fuse cover is marked.

take the radiator cap off and start it up,watch the coolant for bubbles,pressure,this will tell you if the head is cracked or the head gasket is bad. if you see a lot of bubbles or pressure,you got cracks or blown head gasket,expensive fix.also check to see if you have flow,this will test your water pump. also let it run for a while and check the temp as you are running it,does it build up as quick as with the cap on?good test of the head cracked theory.

for the thermostat,just pull it out and get another one with a new gasket,as the gasket is tin,one time use.

just a few things to look for.
 
   / RTV900 overheating, cooling fan off #3  
My 2006 RTV900 has started overheating after running for about 20 minutes. I noticed that the cooling fan is not coming on. Has anyone had this issue before. Is it most likely a fuse or a bad fan?

Any links to a wring diagram?
I have the same problem, but only when plowing snow. I've not had a problem in normal use. I checked the fuse and all were fine, so I took the wire off the temp sensor to check to see the fan was working. It was, so I just bypassed the sensor and hooked up a switch so I can turn it on when I need it.
 
   / RTV900 overheating, cooling fan off #4  
sometimes they will overheat also if you are trying to do something in high range instead of medium,or low.i usually test toe ones i repair by running it around in high on a few hills round the shop.this way i can tell if the fan does come on or not,and if it will overheat or not.usually i cannot get them to overheat,but will run in the upper range of the gauge.
 
   / RTV900 overheating, cooling fan off #5  
I have the same problem. Fan runs when hot wired. I replaced the temp sensor with no change. Have thought of manual switch. I can't locate the fuse box. Can someone share it's location?
 
   / RTV900 overheating, cooling fan off #6  
i had this issue. mine was the temp sensor.
 
   / RTV900 overheating, cooling fan off #7  
Uncle Doug,
I would be looking at the head gasket, they are know to start leaking. 20 minutes is not a long time and it's a 2006.

But do try the fan first. I believe the sensor is on the left side of the engine block closer to the front under the exhaust.

With the key on and touching the wire that hooks to the sensor, should make the fan come on.

Sensor just grounds out that wire to make the fan start.

Easy to splice a wire into that wire, then to a switch that has the other side of the switch going to ground.

See the fan has power going to it all the time, it's just waiting for the sensor to ground out when the engine starts to overheat.

Switch on the dash will let you control when it comes on, but the engine sensor should be doing that when working normally.

Good Luck.
 
   / RTV900 overheating, cooling fan off #8  
We had a cascade - wife was using our 2008(ish) RTV900 and complained it was "smoking". Ends up the radiator cracked on the top and it was steam. Possibly related: a few days before the temp gauge died. Replaced the radiator and noticed the electric fan was not running, and gauge was still busted (no big surprise there). Replaced the water temp sensor in the rear since that was suppose to drive the gauge, no change. Tried grounding the sensor wire (per above) and no change on the gauge either. Did test the fan temp sensor near the thermostat per the instructions above (thanks for that!) and the fan kicked right on, so have order a replacement for that one. Oh, also found the 50amp fan fuse was blown (amazed that Kubota provides spare fuses). So a host of problems. Thinking the fan water temp sensor died, that caused the electric fan to die, which overheated the radiator and it cracked in response? No sure why the fan fuse was blown. Still don't have a clue on the gauge not working. Suppose it could be wiring or for some reason the gauge also died? Basically replacing one part at a time, but really want a functional temp gauge. Open to suggestions for diagnosing it beyond the grounding its sensor.

Fortunately, engine seems fine. We did replace the thermostat when we did the radiator, but the old one tested fine is a pan of hot water. Did a filter and fluid change while we have it out of service just for good measure (and it was about the right time). In any case, any old overheated oil is now history.
 
 
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