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I bought a fan relay / wiring kit for my eclectic fans off ebay, it works as it should, but because its a 185 on 165 off the fans never turn off... i have a 180 thermostat.
i tried to put a resistor inline from the temp sensor to the relay, but it might have been too much because the fans never came on after that and i let it get to 215.
its hard to find anything like this on the internet but i did see one guy who said he needed 4500ohms to lower the temp about 10 degrees? i put a 6000omh resistor in and they never come on.
anyone know anything about this and what i can do to make the fans come on later, i can't find a relay that will be a direct swap with the one i have. i've seen relays like it but how do i know when it will come on? what determines when it clicks on? is it in the coolant temp sender??? it looks just like a normal one
I had an issue trying to run both fans with one controller on mine. The issue I had was it drew too many amps and would fry the relay. I ended up using two relays one for each fan and was able to set two different on/off settings.
I had an issue trying to run both fans with one controller on mine. The issue I had was it drew too many amps and would fry the relay. I ended up using two relays one for each fan and was able to set two different on/off settings.
It works fine as is just turns on and off at temp I don't want.
You can run 100 fans off one relay as long as the relay can handle enough amps
Does anyone know about putting a resistor inline with the temp sensor
Last edited by johnnyb15; Dec 23, 2020 at 05:56 PM.
I could be wrong but I believe what you have is a temperature switch. I believe the discussion about adding a resistor would be in a temperature sensor application where the sensor varies the resistance based on the temperature and provide a temperature indication. In an electric fan setup the switch closes at a setpoint 185 in your case and grounds the wire attached to it. The current flow through that wire closes the relay/s to turn the fan/s on. You should be able to select a switch that will have the closing and opening setpoints more in line with what you want. It is a simple setup but the down side is that you can't select different temperature settings on the fly. I got a switch with my Dewitt dual fan/dual relay setup but opted to use the Edelbrock Pro Flo 4 ECU to control my fans individually. Good luck.
Yes that is exactly what myself and another poster have mentioned. It is a ground switch that completes the ground circuit at 185 degrees and opens when it hits 165.
Yes that is exactly what myself and another poster have mentioned. It is a ground switch that completes the ground circuit at 185 degrees and opens when it hits 165.
ok that makes sense now, you can buy these all over. i will find one with the right temps i want
I would highly recommend you use 2 relays, one for each fan. Well, everything in the power circuit, separate wires to each relay and a fuse for each fan. It can help you get home when something goes wrong since you only lose one fan.
I would highly recommend you use 2 relays, one for each fan. Well, everything in the power circuit, separate wires to each relay and a fuse for each fan. It can help you get home when something goes wrong since you only lose one fan.
I have mine wired exactly as you reccomend but I can't get it to work. If I ground the wires to the sending unit the fan comes on. My sending unit is brass and located in my aluminum manifold. I tried grounding the sending unit to a bolt on engine didn't help. Any ideas?
Last edited by talentscout; Feb 1, 2021 at 08:23 PM.
electric fan relay on / off
