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2006 Yamaha Rhino 660 - temp light coming on?

13K views 20 replies 8 participants last post by  Solderboy 
#1 ·
New to me Rhino 660 and the temp light comes in after some light use? New coolant and radiator checked. Fan is working also. Went to a dealership and talked to a maintenance guy and he said thermostat? But I didn’t think an 06 had a thermostat? Coolant air pocket maybe but I figured it would have worked out by driving it some since then. Just scratching my head as to what it could be. Thanks I’m advance!
 
#2 ·
None of the 660’s have thermostat, u need to bleed the system, dont count on it working its way out. There are youtube vids on how to properly bleed coolant lines on a rhino


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#4 ·
Be sure to jack up the front end to help get any air out. I always clean the radiator front to back and back to front.
 
#5 ·
Thanks all! Yeah I thought it didn't have a thermostate but the mechanic insisted, lol. Anyway, I can take that back no problem. The machine is at the farm so I am going to bring it back to the house and clean it. How is the best way to ensure I get it as clean as possible? Just use a power washer?

I don't believe this would make a difference but right after I got it I installed a big winch in the front (where it was supposed to go) of the radiator. 5K lb winch. It is a couple inches away from the radiator but any chance that addition could block some needed air flow?

Thanks again!
 
#6 ·
Post a pic but it could b that if its dirty and u cut off some airflow its possible


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#7 ·
Doubt the winch is the problem, I just put dish soap in a spray bottle and saturate the rad both sides then regular water hose with spray nozzle. Have you tested the water to see if it's getting hot or just going by the temp light? you might take the rad cap off start the rhino and see if the water starts moving. If your running slow you may not be getting enough air flow. If I run into the wind I'll run 185 to 190 and if I turn and run with wind I'll hit 200 to 210 per my gauge the idiot light doesn't come on.
 
#8 ·
I haven’t tested the temp nor the coolant for that matter as i just know the light is coming on. She does smell a little warm to me though when it comes on. However I do plan to test both. The coolant seems an odd color to me - very light bluish color and very clean. Not sure who makes a bluish coolant though - Suzuki maybe ? Not really sure what type coolant to add back either? I wonder if it’s got way too much water in it and not enough coolant given the color. I’m gonna test that also. I’m gonna bleed the coolant system as well. Then clean the fins. There was a good coating of mud on the inside when i got it. While their appearance may look okay they could be clear. Would a power washer be too much power for cleaning the fins?
 
#10 ·
Messed with the Rhino some this afternoon. Installed a marine primer bulb which dramatically helped the starting. Next i took the radiator cap off and started the engine to see if the coolant was moving and it was. Next I jacked the front up about a foot and bleed the two bleeder valves off the coolant system. There could of been some small air pockets in the system but I don’t believe there was much if any air. Either way I can check that off my list.

The radiator over flow tank was maybe 3/4” low from being completely full. I topped it off and noticed the hose connecting the over flow tank to the top of the radiator had a kink in the line at the top. I tried to straighten it up but it needs to be replaced. There was a small Split in the over flow line at the other end near the bottom of the over flow tank. I ran it enough after that to get the fan to come on and make sure it was pulling air. Gonna try to clean the radiator next and see if that helps. Not sure what else to try after that.
 
#11 ·
I know on ATV’s that I have had the cooling fan would run after your turned the key off until it got the temp under control. On the Rhino it only runs when the key is on - just curious if anyone has wired it to run with the key off? Most of our use will be short drives with stop and go work on the farm so I’m curious if that is also contributing to the temp light. While new to the Rhino I can’t believe that the temp light coming on given how little we are using it is normal. Has anybody ever installed a shroud or larger fan?
 
#12 ·
There are fan override kits out there, have you thought about installing a temp gauge so u can actually see what its doing


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#14 ·
First step is to measure the water temp so you can determine if it's truly getting hot or it's something else. I found the quickest way to double check my water temp is to buy the radiator cap with an integrated manual temp gauge....I think I got mine from RockyMountainATV.com.

UTV parts vendors and Ebay have bolt-on aftermarket fan shrouds you can purchase that should help with airflow, in theory.....never tried them myself.
 
#15 ·
First step is to measure the water temp so you can determine if it's truly getting hot or it's something else. I found the quickest way to double check my water temp is to buy the radiator cap with an integrated manual temp gauge....I think I got mine from RockyMountainATV.com.

UTV parts vendors and Ebay have bolt-on aftermarket fan shrouds you can purchase that should help with airflow, in theory.....never tried them myself.

https://www.rockymountainatvmc.com/...radiator-cap-with-temperature-gauge-p?v=10244 ($25)


Just checked Amazon prices - above much better deal!
 
#20 ·
Too Hot?



Not discounting anything anyone else has stated but I had a similar problem with my bone stock 2005 660. My biggest issue was the light was coming on but it wasn't boiling over into the overflow tank so I suspected it really wasn't getting too hot. First thing I did was drain the cooling system and refill it with 50-50 Prestone (don't forget to jack up the front end and bleed the system). That didn't make a noticeable improvement. Next, I pulled the radiator and after cleaning it (wasn't too bad) I installed a shroud. I could get you the part number if you need it. Again not a noticeable improvement EXCEPT, the fan run time was cut in half; the shroud really works well! Finally, after talking with the guys at Cheap Cycle Parts, we decided I had the incorrect, or defective thermo switch. I ordered part # 5KM-82560-00-00 (Thermo Switch Assembly). Why, because I don't think my Rhino originally came with the speedometer assembly and when whomever added that forgot, or didn't know to, change the thermo switch to the proper one.

In the end, my light has not come on since. So you could have a defective or incorrect thermo switch. One final thing, while the machine was jacked up I ran it with the radiator cap off even after bleeding it at the head. Looking in the radiator, there were visible bubbles and air pockets still in the system so my advice is to also run it until it warms up with the cap off to assure no air is in the system. Top it off once it cools down.

I hope that helps!
 
#21 ·
I have a 04 660 that I have put a temp gauge on so that I can monitor the temp while I ride. I pulled out the stock sensor and grounded the wire to turn off the light on the dash, but the light still comes on intermittently I have checked the wiring and ohmed out the circuit everything there checks out.I do have the optional digital dash installed. With that dash is the sensor supposed to have a variable sensor or is it just a thermostatic switch? I also have an aftermarket CDI installed my previous one went out.
 
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