variable speed fan control


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Old 10-22-07, 12:20 PM
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variable speed fan control

I just finished installing electric fans on my hot rod. Wow, what a noticable difference in power. My problem is that the fans dont really need to run at high speed all the time. Only when engine temperature gets higher than normal or when the A/c is on. How can I reduce voltage until the temperature increases? Right now the system is wired with a predetermined thermostat, bosch type relay,and toggle switch. When temp. reaches normal, fans comes on. Switch is there to manually override thermostat.Thanks.
 
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Old 10-22-07, 01:30 PM
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typical 2 speed fans use a resistor to lower voltage and 2 relays one for low speed and one for high speed however the relays are typically controlled by a computer but you could probably do the same with 2 thermostats set at different temps one thermostat for low speed and one set at a slightly higher temp controlling the high speed relay.
they also make variable speed controls for aftermarket fans might check the link below for an example if you dont want to wire one up with a resistor and dual thermostats.
http://store.summitracing.com/partde...5&autoview=sku
 
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Old 10-22-07, 03:23 PM
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Since I already have the switches, relays, and thermostat, I was wanting to wire this up myself. No need to speed 95 bucks at Summit. Can you tell me more about the resistor and how to wire it. Thanks.
 
 

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