fan switch wiring
Posted: 02 Dec 2003, 08:16
Hello all,
After running for several months with my radiator fan wired directly to a switch on the dashboard (i.e. manual control only), I decided to return to the convenience of automatic operation by installing a new thermo switch on the radiator. I ordered a two-wire model, but the supplier sent me a three-wire switch which has three black wires: two with spade connectors and one with a bullet connector. I connected the switch using the two spade connectors, since my fan set-up only ever had two wires. The switch works, but judging by the temperature gauge, it is switching the fan on a lot later than my previous switch did, and it doesn't seem to stay on for very long.
Someone suggested to me that the reason why there are three wires on the new switch might be that it is intended for a more modern car with a two-speed fan, so the fan would spin at low speed at say 90 degrees C then at high speed when the temperature rose to say 97 deg. Is that correct? I'm wondering whether I've simply wired my single-speed fan to the hotter setting on the switch, in which case, presumably, one of the spade connectors and the bullet connector ought to give me the cooler setting. Anyone had this problem? Those stressful few minutes watching the temperature gauge climb are not good for my health!
Cheers.
Andy
After running for several months with my radiator fan wired directly to a switch on the dashboard (i.e. manual control only), I decided to return to the convenience of automatic operation by installing a new thermo switch on the radiator. I ordered a two-wire model, but the supplier sent me a three-wire switch which has three black wires: two with spade connectors and one with a bullet connector. I connected the switch using the two spade connectors, since my fan set-up only ever had two wires. The switch works, but judging by the temperature gauge, it is switching the fan on a lot later than my previous switch did, and it doesn't seem to stay on for very long.
Someone suggested to me that the reason why there are three wires on the new switch might be that it is intended for a more modern car with a two-speed fan, so the fan would spin at low speed at say 90 degrees C then at high speed when the temperature rose to say 97 deg. Is that correct? I'm wondering whether I've simply wired my single-speed fan to the hotter setting on the switch, in which case, presumably, one of the spade connectors and the bullet connector ought to give me the cooler setting. Anyone had this problem? Those stressful few minutes watching the temperature gauge climb are not good for my health!
Cheers.
Andy