[Jpcz]

Hi there! New to the forum and I have been reading for a while. I was just so stuck that I decided I needed to create an account and ask for help.

I just bought a 99 450es with a plow. Everything was good until tonight when the oil light stayed on before starting. It wasn't run all day so no way oil temps were too hot. I turned the key off to let it sit for a while and tried again a few times...same issue.

So I read here the way to test the fan to troubleshoot. I've been searching for a while but cannot find the wire. Dumb question but I'll ask it anyway...is that because I have the plow mount underneath? Everything I read says it should be easy to find...

Is there another way to test the fan to make sure it's working correctly, assuming the mount is preventing easy access to this wire into the sensor.

To make matters even weirder, the Light eventually turned off after I rode it around for 5mins. After I parked it, I let it sit for a little bit and now, when I turn the key the light comes on and quickly goes off just like it should. It's back to normal operation and the light won't stay on anymore. Seems like that might signal a bad sensor or even as simple as a bad connection. But that brings me back to square one and being unable to find this connection.

Any help would be awesome! Thank you

 

[Goober]

This has happened to my 99 450S. If you look in the service manual there’s a troubleshooting guide; the guide will point you to two modules—at this time I can’t remember exactly which they are.
I had the shop replace both of them because i was told it’s hard to tell which is failing. After I read the guide I suspected that was so

 

[fishfiles]

Quote jpcz "
I've been searching for a while but cannot find the wire. " Quote

remove the seat , then the plastic over the tank , then the tank , on the left side are blue and green wires with bullet connectors , those are the fan wires , blue is power , green is ground

 

[mrbb]

also it could be your oil temp sensor that is bad
and last the motor doesn;'t have to run all day for the temp /fan to come on, if left idling for a while it can get hot enough to turn it on, as idling doesn't add any air flow to help cool and such,m not the best thing to do, there not made to idle for long periods
also, its not HOW Long a motor is run to raise temps, but how its being used, plow a ton or work a motor a bunch in a short period of time and you can raise temps WAY up fast!

but the oil temo sensors, have been more of a weak link in my experience than the fan control units!
I have replaced 3 oil temp sensors on my 400 and just one fan control unit in the 20 yrs I have owned mine?

 

[Jpcz]

I certainly haven't ridden it enough or hard enough to get hot enough for the fan to need to lock on. Was just hoping to get ahead of this, as it will be what I plow my driveway with.

Figured I'd start the diagnosis steps but couldn't find the oil temp sensor wire to ground to see if fan comes on. But then all of a sudden the light stopped staying on and now everything appears normal.

Not sure where to go with this anymore without any problem symptoms showing up. I've got to change the oil anyway so maybe I'll get a new temp sensor and install that at the same time. I guess I'll have to take the plow bracket off to get to it though.

 

[SamUK]

Might be worth cleaning the oil cooler inside and out, years of neglect prior to your ownership could see thebinside of the cooler partially blocked and restricting the oil flow somewhat.

 

[Goober]

I hope you will be able to fix this. I was looking thru my paperwork.
My oil light would stay on and only go out if you revved it or rode it. I began to think it was the pump or oil temp sensor. The fan never came on and shouldn’t come on–I’ve had to drive mine in first gear up a long hill for five minutes on a hot day before the fan would come on.
Turns out the shop replaced the fan control unit (38710-HM7-004); it was $190.
To encourage your reply I’ve posted a pic of one of my work rigs an 00 450S with a 1.5 inch lift and Bobcat fairing.