I would like to make sure the electric radiator fan is working properly on the RTV900. Does any one have any info on the circuitry or a wiring diagram. Also we are replacing the head gasket and the head bolts are supposed to be torqued after running 30 minutes. Does that mean re-torqued when the motor is hot after the 30 minute run, or run 30 minutes, let it cool , and then retorque? Thank You!
RTV 900 Questions
- Thread starter texczech
- Start date
Hi, My book doesn't say about the hot or cold tightening but I think it would be after it has cooled off to get proper adjustment but then again, I don't know for sure. I imagine someone that is a real mechanic will chime in on this. I will check on the radiator fan tonight . Bordercollie
SpudHauler
Active member
Torgue when everything is cool, 4 hr shut down or overnight. Never hot.
You can disconnect the fan and test it by jumping its connection directly to the battery with the unit off . More later . Bordercollie
Have you heard the fan cut on? I can sometimes hear mine cut on when I'm idling after working it hard. Sometimes I can turn the key to the glow plug position and will hear the fan cut on if I have been running it just before. There is also a coolant temperature switch which is just above the alternator and looks sort of like a spark plug . The coolant temperature sensor is located on the top of engine near the injectors. The fan relay is mounted on the back board of the fuse area. Bordercollie
SpudHauler
Active member
Okay, so you are replacing a head gasket, possibly because of overheating.
I would replace the thermostat, water temperature switch and coolant. Get a good brand name coolant (like Prestone) and original thermostat and water temperature switch.
To test the fan before doing anything, the wire diagram attached for an 11 shows the water temperature switch is simply grounding the circuit. So pull the black wire from the switch and ground it and the fan should come on. Or if you ground the one wire that goes to the water temperature switch the same thing should happen. Key on of course. Although it may work even with key off. Not sure. I sold my 900 manual with the old machine so someone else may have better wire info.
Other possibility is rad could have dirt of chaff in the fins and blocking some of it's cooling capacity. Carefully clean the rad, trying not to bend any of the fin work or poke any holes in it. NOT good. Water is a good cleaner, spray both sides and hold light behind to make sure you can see through all areas of the rad. Most dirt will be in the bottom rows.
File is too big to upload. Sorry no wire diagram.
If you are electrically inclined it would be very easy to place a switch in the wire going to the water temperature switch and have it feed from the original wire to one side of your switch and the other side go to ground. This way if the water temperature switch didn't activate your fan you could manually turn it on by flipping the switch. Good solution for cases where you are working the machine hard and want extra cooling for short periods. Other wise the water temperature switch would still handle the fan coming on when the engine requires it. Confused? Nothing is easy. You are just giving the fan two options of operation. Manual by you and the switch or as the factory provided by the water temp switch as per normal.
I would replace the thermostat, water temperature switch and coolant. Get a good brand name coolant (like Prestone) and original thermostat and water temperature switch.
To test the fan before doing anything, the wire diagram attached for an 11 shows the water temperature switch is simply grounding the circuit. So pull the black wire from the switch and ground it and the fan should come on. Or if you ground the one wire that goes to the water temperature switch the same thing should happen. Key on of course. Although it may work even with key off. Not sure. I sold my 900 manual with the old machine so someone else may have better wire info.
Other possibility is rad could have dirt of chaff in the fins and blocking some of it's cooling capacity. Carefully clean the rad, trying not to bend any of the fin work or poke any holes in it. NOT good. Water is a good cleaner, spray both sides and hold light behind to make sure you can see through all areas of the rad. Most dirt will be in the bottom rows.
File is too big to upload. Sorry no wire diagram.
If you are electrically inclined it would be very easy to place a switch in the wire going to the water temperature switch and have it feed from the original wire to one side of your switch and the other side go to ground. This way if the water temperature switch didn't activate your fan you could manually turn it on by flipping the switch. Good solution for cases where you are working the machine hard and want extra cooling for short periods. Other wise the water temperature switch would still handle the fan coming on when the engine requires it. Confused? Nothing is easy. You are just giving the fan two options of operation. Manual by you and the switch or as the factory provided by the water temp switch as per normal.