Radiator fan wont turn on

John sounds like your sensor may be bad. Next it could be your thermostat sticking use a temp gun and measure the temp of your radiator at the cap. Do not remove cap. Just take temp. If it is getting hot it should spit water out. Check to see if the electric fan is coming on the sensor to cut the fan on maybe bad or the fan. Hope this helps.

If the steam is rising from the radiator and not from the overflow tank or hose then you do have a leak.. in the radiator. check for a cracked tank or fitting where the hoses connect. If it is making steam the guage is probably defective. Find out where that steam is coming from ! If the car is making steam the rad fan should probably be running.. I do not know about your particular car but some times the secon fan only comes on with A/C use or extream heat.

well for one replace the radiator cap, thats a closed system and shouldn't be boiling over like that , Now Just so ya know, Grand Voyagers and Caravans are known for blowing head gaskets, and as they leak it turns to steam, and right out the exhaust pipe, so have a compression test done on your motor, to be sure those are ok, the rapid rise and fall in the temp is just the thermostat opening once the desired temp is reached

hi this could be caused by a couple of things, thermostat not opening is one of the main one, fan heater switch on the radiator is another, and obviously water leak is another, the first one thermostat, can replaced relatively cheaply, for a few bucks, you could do it yourself if you have the correct tools, to find out if it is thermostat, fill water first, run motor till it starts to get hot, feel the hoses on either side of the radiator ( top and bottom hoses be careful not to burn yourself in the process) if one is very hot, and the other is warm to cold, that will be the thermostat, second, the radiator fan switch, fill water, run motor, watch temp Gage, if by the time it has reached over half way on the temp Gage and the rad fan has still not cut in then this is normally a sign the switch on the radiator is u/s and needs replacing ( check fuse for fan to and relay this will also stop fan from working ) also to check for leaks, fill water, ( try not to spill any ) then if available a large cloth or sheet under car, run engine ( making sure first the other items have been checked ) and just observe for dripping water hope this helps

once the truck is fully warmed up, feel the 2 heater hoses going through the firewall in the engine compartment. they should be hot to the touch. if they are, then the problem is most likely the heater controls, such as the temp. switch on the dash or the blend door itself inside the dash. if they are cool, check that the coolant is completely full. just because the temp gauge reads normal doesn't mean there's enough coolant in the system to fill the heater core. remove the radiator cap once cooled and top off if needed. if it is, or was, low, its possible to get air the the cooling system and block flow of coolant to heater core.

check the fan and water pump one of these is possibly ur problem when ur at idle there is no heat load and the radiator can dissipate that when ur driving causes more heat if fan isnt working the car wont cool same if problem is water pump at idle pump may be able to move some of the hot anti-freeze but when driving may not be pumping it thru radiator to cool

The fans are actuated by coolant temp in the radiator. It is possible to have overheated coolant in the radiator, causing the steam, and your engine not overheating...the temp sensor for your engine is reflecting the engine temp, not the temp of the coolant in the radiator. You problem could be a bad temp sensor at the radiator...not allowing the fans to come on. Good Luck! I hope you find this to be very helpful!

You need to diagnose the problem. The fan is doing what it is being told to do by the computer. You stated the temp gage on the dash is in the HOT position. Either the engine is very hot and the fan needs to run to remove heat even after it is shut off or the gage, coolant sensor or temp sender is defective. Try running it temporarly without a thermostat and see what happens, you may have bought a defective thermostat.

Start with engine cool, & remove radiator cap. Check level in rad & fill to an inch or so from top of rad. Start car & turn heater on.(not defrost)
Now let it run until engine gets up to normal operating temperature & let it run until rad fan comes on & off, 2 or 3 times. Rev engine slightly every so often just to help disperse air in system faster. Fill rad as needed during this time. After you do that, and fan has come on & off 2 or 3 times, put rad cap back on & fill return bottle to proper mark, then see how it is.
I suspect it's just air in system & this should cure that . If not get back to me.

check first if you are loosing water or cooling fluids on your radiator. There may be a leak or the radiator cap may no longer prevent the steam from escaping. check the radiator fans if they are turning. You can check the fan if it is working by removing the temp sensor at the lower radiator hose. The fan should turn on by then.