OliPre94 Posted July 15, 2023 Share Posted July 15, 2023 Hi all, Trying to fine tune the thermostat (controller) on my Revotec Electric Fan. As it is, the fan kicks in about 5/10 minutes within a journey and will stay on so it's set too low. I hear that it's only supposed to kick in when it gets too hot so its not running constantly. What's the best way to set up the fan? Its probably so simple but I want to make sure it's right. Thanks for the help in advance Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 15, 2023 Share Posted July 15, 2023 What engine? Do you know what temperature thermostat you've got fitted? Quote Link to comment Share on other sites More sharing options...
OliPre94 Posted July 16, 2023 Author Share Posted July 16, 2023 8 hours ago, FridgeFreezer said: What engine? Do you know what temperature thermostat you've got fitted? Hi there, I have a 2.5n/a (old school defender I know 😂) and I fitted a 82deg thermostat Quote Link to comment Share on other sites More sharing options...
Snagger Posted July 16, 2023 Share Posted July 16, 2023 Is the thermostatic switch in the top or bottom hose? Is should be in the bottom, so that the fan only activates when the radiator isn’t doing enough unassisted. If you have the switch in the top hose, the fan will run before the engine is even up to normal temperature and will continue for some time after shut-off (unless the power feed is through an ignition switch output). 1 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 17, 2023 Share Posted July 17, 2023 23 hours ago, Snagger said: Is the thermostatic switch in the top or bottom hose? Is should be in the bottom, so that the fan only activates when the radiator isn’t doing enough unassisted. If you have the switch in the top hose, the fan will run before the engine is even up to normal temperature and will continue for some time after shut-off (unless the power feed is through an ignition switch output). Depends what temperature it's set to - plenty of cars have their switch / sensor in the top or half way down the rad. Mine's driven from the ECU (sensed at the top near the stat) but only comes on once it's above the "fully open" temperature of the stat. An 82deg stat probably won't be fully open until nearly 90deg, so setting the fan lower than that is overkill - but of course the way LR make temperature gauges that could look uncomfortably hot. Quote Link to comment Share on other sites More sharing options...
OliPre94 Posted July 17, 2023 Author Share Posted July 17, 2023 1 hour ago, FridgeFreezer said: Depends what temperature it's set to - plenty of cars have their switch / sensor in the top or half way down the rad. Mine's driven from the ECU (sensed at the top near the stat) but only comes on once it's above the "fully open" temperature of the stat. An 82deg stat probably won't be fully open until nearly 90deg, so setting the fan lower than that is overkill - but of course the way LR make temperature gauges that could look uncomfortably hot. My controller is on the top hose from the rad just before the thermostat. What I did yesterday was take the Land Rover for a drive and whenever the fan kicked in I just turned the fan up just enough so it cut off and kept doing that until it didn't come on again. That puts me in this territory of not actually knowing how hot the engine is running but it sits comfortably in the middle of the temp guage. I may get a temperature gun and point it at the controller and see what temperature the fan is kicking in at. I'm assuming the normal engine operating temp for a 2.5n/a is around 90deg so I want the fan controller setup around the 95deg point for the fan to kick in. Quote Link to comment Share on other sites More sharing options...
Sausages Posted July 17, 2023 Share Posted July 17, 2023 I have mine in the top hose and this is what I did. It comes on and off as necessary. I also have the power feed coming from an ignition switched aux fuse box, so it can’t run with engine off. Quote Link to comment Share on other sites More sharing options...
OliPre94 Posted July 17, 2023 Author Share Posted July 17, 2023 25 minutes ago, Sausages said: I have mine in the top hose and this is what I did. It comes on and off as necessary. I also have the power feed coming from an ignition switched aux fuse box, so it can’t run with engine off. This is the same setup that I have, it will only power up with the ignition on. For me the only issue is fine tuning the thermostat controller so the fan only kicks in when it's needed too Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 17, 2023 Share Posted July 17, 2023 25 minutes ago, OliPre94 said: For me the only issue is fine tuning the thermostat controller so the fan only kicks in when it's needed too I guess the controller design means you're kinda stuck with that, assuming there's no markings on it that tell you a useful temperature range? Quote Link to comment Share on other sites More sharing options...
OliPre94 Posted July 17, 2023 Author Share Posted July 17, 2023 1 hour ago, FridgeFreezer said: I guess the controller design means you're kinda stuck with that, assuming there's no markings on it that tell you a useful temperature range? That's correct there are no markings giving a temperature. Apparently the dial goes between 70 and 120 deg so something in the middle would be my 95deg mark but how accurate that is I don't know Quote Link to comment Share on other sites More sharing options...
dangerous doug Posted July 17, 2023 Share Posted July 17, 2023 It should have markings on the controller, mine does but you need a microscope to see. I would also go over all the connections of those fans as I’ve had nothing but problems with them but maybe they were a Friday afternoon set Quote Link to comment Share on other sites More sharing options...
OliPre94 Posted July 17, 2023 Author Share Posted July 17, 2023 5 hours ago, dangerous doug said: It should have markings on the controller, mine does but you need a microscope to see. I would also go over all the connections of those fans as I’ve had nothing but problems with them but maybe they were a Friday afternoon set The connections seem fine and it kicks in and out when commanded through the controller thermostat. It's just knowing exactly what to set it too. I had a look and I do have markings but they dont represent any temperature scale just a bunch of letters with random numbers. The whole dial adjustment range is 3/4 of a turn and that's 70 - 120deg. I would guess that mine is currently set to between 100 - 110deg for the fan to kick in judging from where the dial is. Quote Link to comment Share on other sites More sharing options...
Snagger Posted July 18, 2023 Share Posted July 18, 2023 The problem with top hose switches is that they activate the fan when the engine reaches a higher temperature than it should comfortably run at, where as a bottom hose switch will trigger the fan when the radiator outlet temperature is above ideal but before the engine temperature starts becoming excessive and will ensure that the rad output is brought back to where it should be to cool the engine. Either will work, but I think the bottom hose system is simpler, more pre-emotive and more reliable. The adjustable Kenlowe top hose triggers don’t enjoy a good reputation, even though their fans are fine (if overpriced). 2 Quote Link to comment Share on other sites More sharing options...
AlWorms Posted July 18, 2023 Share Posted July 18, 2023 1 hour ago, Snagger said: the bottom hose system is simpler, more pre-emotive and more reliable. Correct. Other than the coolant temp IN the block/heads, the radiator return/outlet is the only other important temperature. It makes no difference if the radiator inlet is 50C or 100c... it's ONLY the radiator outlet temp that determines if the engine can be cooled sufficiently - the radiator outlet temp MUST be lower than the current block coolant temperature for any useful cooling to happen. Running a radiator inlet sensor; the fan can run when the radiator inlet temp is high, but the radiator may be cooling the coolant more than sufficiently. So if you have 90c going into the radiator and 50c coming out, a top hose sensor may run the fan anyway, where as a bottom hose sensor stays off as the radiator is working as intended and 50c is still well below where the fans need to be on. 1 Quote Link to comment Share on other sites More sharing options...
miketomcat Posted July 18, 2023 Share Posted July 18, 2023 (edited) Mine is a 200tdi, the sensor is a fixed temperature switch of 98°c it's mounted it the second spigot on the top thermostat housing (I drilled and tapped it out). My fan only kicks in after a long higher speed run or in hot weather, so I works exactly as it should and I'm happy with the position (not getting into a top/bottom hose debate as there's good arguments for each). For your set up the way you've set it is exactly how I would and I would be happy with that, at the end of the day the fan is not a substitute for keeping an eye on the guage. You know what temperature the engine runs happily at on your gauge so if it stays roughly there and the fans not running excessively I'd leave it as is. Mike Edited July 18, 2023 by miketomcat Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 18, 2023 Share Posted July 18, 2023 5 hours ago, Snagger said: The adjustable Kenlowe top hose triggers don’t enjoy a good reputation That's nothing to do with where you put them, the correct place to mount them is in the bin, along with their stupid radiator-damaging fan mounts. 1 1 Quote Link to comment Share on other sites More sharing options...
dangerous doug Posted July 18, 2023 Share Posted July 18, 2023 5 minutes ago, FridgeFreezer said: That's nothing to do with where you put them, the correct place to mount them is in the bin, along with their stupid radiator-damaging fan mounts. Aaaaah the notorious rat tail zip tie. I trust a pair of chocolate pants more than those things 1 2 Quote Link to comment Share on other sites More sharing options...
ped Posted July 18, 2023 Share Posted July 18, 2023 in the past i always used the top hose for the fan temp switch using the lower temp setting of the two output terminals,used in conjunction with a gauge that reads degrees with a manual overide i would put on if i was in low box or towing up hills for the 300 i have fitted it in the bottom hose (more for conveniance as the 300 top hose is a bit short to get the sender housing into Quote Link to comment Share on other sites More sharing options...
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