Relay, Electric fans

 I installed 2 electric fans (cooling, vehicle) 1 is a manual only, switched, the other is dual control, switched, and thermostat controlled. I want to, or think I should install relays for both because of the amp draw. Could someone help me out on how to wire in relays for both? I think I can use a SPST for the manual, and a SPDT for the dual? Thanks for any help...Chuck

P.S. I also need the switch on the thermostat controlled fan to over ride the thermostat and be controlled manual, "bypassing" the thermostat. If I wire it as one diagram I saw on this site, (thanks) using a SPDT relay, + feed from thermostat to 87A, + feed for fan to 30, convert switch to - feed for 86, and 85 & 87 to fused +? is this the right way? I hope somebody reads this and can send a reply.....Thanks....CMA

I have the same type of problem. I had to hard wire the cooling fan on my integra and it is hooked up to a toggle switch. When I turn it on, it draws a lot of current. Does anyone know what kind of relay would help with this problem? Where do I go and what do I ask for? How do I wire it in? I'd really appreciate help for either of us.

do you want them to come on with your ignition switch at all times. fans always on.gcorrea

Hi; A lot of cars have a temp sensor in the radiator. If you have one, there should be two leads coming off of it. To insure that it works, place a continuity tester on each lead and there should be no continuity. Now heat the sensor by placing it in boiling water and there should be continuity. If it works as described, you can hook one side of the sensor to veh ground. Other side of sensor should be connected to relay pin 85. Relay pin 86 and 87 should be hooked up to 12v. Pin 30 should hook up to the positive side of your fan. This will automatically turn the fans on when the vehicle gets hot, and automatically turn them off when the vehicle cools. If your vehicle has AC, make sure both fans come on when the AC compressor is running. If you need to, use a relay. Pin 85 would connect to ground. Pin 86 would hook up to the positive wire that connects to the AC Compressor. Pin 87 would connect to ground, and pin 30 would connect to pin 85 of the previously discussed relay. This would result in the fan comming on automatically whenever the AC is turned on, or the vehicle gets hot. Pat