View Full Version : temp sensor for elec. fan help please


1Fast69chevy
Mar 30th, 03, 03:50 PM
I have a temp sensor that is for turning my electric fan on and off (the kind that is tapped into the intake) my problem is i cannot find one that is a 180* open switch (closes the circuit at 180*) that can handle 15-20 amps. does anyone know of a temp sensor switch that could do this? or can anyone point me in the right direction?

thanks for your help

rick

[ 03-30-2003, 07:32 PM: Message edited by: 1Fast69chevy ]

Mark C
Mar 30th, 03, 05:15 PM
The temperature switches themselves are usually not capable of switching any kind of significant load. They usually are used to pickup a relay that has contacts that can carry the 20 or 30 amps that the fans require. If you really can't find a switch that closes at 180 degrees you can use an interposing relay that can be used to act as the switch. The interposing relay getds wired so that it is normally energized anytime the key is on and the temperature is below 180 degrees. When the temperature switch opens, it deenergizes the relay. You then use the "B" contact on this relay (the one that is closed when the relay is deenergized) to pick up a second relay which inturn picks up the fan through it's "A" (the one that closes when the relay is energized). It is very important that the power to both of these relays get wired through a circuit that is hot only when the ignition switch is in run, otherwise the fan could run all the time.

1Fast69chevy
Mar 30th, 03, 05:35 PM
the thing is i dont want to run alot of relays to my fan setup, i know they make these heavy duty switches, becuase my dad has one that is a 185* normally closed switch, but i would need a normally open one. Norton is the company that made it, but i cant find any info on those, or the company.

any ideas?
rick

Toby Keen
Mar 31st, 03, 12:00 AM
I'm not positive on this but Spal might have the answer to your question. A good speed shop will have information on Spal.

mikestr
Mar 31st, 03, 05:41 AM
As recommended, SPAL does sell the complete wiring setup including the relay and temp sensor.