ISX Fan Running

Yes, that is correct that there are several sources of signals sent to the ecm and then the controller. If the controller itself is indeed bad, it is a pricey little thing, from what I understand. Source engineering has a wax valve kit to replace the controller at a little lower price if interested. Happy Trails Bert

johnsonbert wrote:
We have an ISL 400 in ours, in the left of the engine compartment there is a fan controller switch that controls the fan speed by controlling the hyd pump to the fan motor. It is by Sauer Danfoss and is about 2 1/2" square with a little valve on top. If yours is the same, it will have a group of wires coming to it and a couple of hyd lines, mine is near the hydraulic filter. The first thing to try is to check the connection. We had this problem on ours, it would intermittently go off and on at will. If there is no connection, or bad connection, it will run wide open all the time. Cleaning the connections on ours solved the problem. There is a monaco specific thread on irv2.com which will be your friend in this and many matters Monaco related. Congrats on the new rig and enjoy. Hope this may help, Happy Trails Bert

if the hydralic fan speed switch is disconnected it will run wide open by factory default.Its designed to work this way in case the wire harness were to get ripped off so engine will not over heat
this unit is also controlled by signals sent to ecm by temperature sensors so you may have a bad engine sensor or a bad control switch

We have an ISL 400 in ours, in the left of the engine compartment there is a fan controller switch that controls the fan speed by controlling the hyd pump to the fan motor. It is by Sauer Danfoss and is about 2 1/2" square with a little valve on top. If yours is the same, it will have a group of wires coming to it and a couple of hyd lines, mine is near the hydraulic filter. The first thing to try is to check the connection. We had this problem on ours, it would intermittently go off and on at will. If there is no connection, or bad connection, it will run wide open all the time. Cleaning the connections on ours solved the problem. There is a monaco specific thread on irv2.com which will be your friend in this and many matters Monaco related. Congrats on the new rig and enjoy. Hope this may help, Happy Trails Bert

Thank you, we have been looking and not finding anything.

Yes you have a problem... in the meantime this may help: http://www.irv2.com/forums/f115/side-radiator-wax-valve-replacement-148331.html
Not saying this is the cause of your problem but it is a common reason for it running at high speed when not needed. Will give you a better idea how your system works.

Thanks Ivylog we will check out Monacoers. I believe its not right. The fan blows like that when the engine starts till it shuts off.
Thank you

I would suggest joining the Yahoo group Monacoers... lots of info and this issue has been discussed with parts/repair info. If it stirs up dust in the first mile after starting you may have a problem. If not then sounds normal.

I guess we need to call them again. Ours is going wide open all the time. One speed. It sounds like a freight train. When your stopped or going slow in a parking lot thats gravel it blows air like crazy.

The fan should not ever stop-- it should go from low speed to high speed.

The reason that you always need some air flow is to cool the intake air from the turbo (happens in the CAC= Charge Air Cooler).

Monaco could tell you want kind of thermostatic control you have.