Electric Fan Controls & Methods - A Hot Topic

Flex-a-lite has introduced the Variable Speed Control module, or VSC. It uses a radiator mounted probe to measure coolant temperature and make adjustments to the electric fan's speed depending on the conditions: as low as 20-percent or 100-percent as cooling needs increase. The VSC can also increase fan output when the A/C is turned on and will run for short periods after the engine is shut off.

To live up to their name, EZ wiring labels the conductors in the fan harness.

Fan Man can provide this complete SPAL relay harness and thermal fan switch kit. The thermal switch can be installed in front of the intake manifold in a water port, the side of a head or in the thermostat housing.

Fan Man also offers a variety of senders. Typically a 180-degree thermostat would use a 195F/180F on-off switch; a 160-degree thermostat would use a 185F/170F on-off switch.

Hot Rod Air recently announced the release of their new dual fan wiring harness specifically designed to safely handle the electrical load of a dual electric fan setup with the use of a single heavy-duty relay. The kit comes complete with 70-amp relay, wiring harness with loom and terminals.

Hotronics has custom machined aluminum temperature senders available separately or with a thermostatic relay pack. On/off temperatures are 180/196F or 210/220F. Thread sizes are 1/2 or 3/8 NPT.

Also available are fan controls that are triggered by the fuel injection system's ECM and fully adjustable styles (shown). The adjustment knob is used to set a precise temperature desired for fan activation. The kit includes the thermostat with bracket, a 30-amp relay, 30-amp circuit breaker, wiring, terminals, and mounting hardware.

Also available is the Cool Down Timer that keeps the electric fan running after the key is turned off. Adjustable run times are from 2 to 41/2 minutes. Delay time is adjusted with small screwdriver through a hole in end of box.

Painless designed the Fan-Thom II kit to provide constant voltage, protection from voltage and amperage spikes and to keep the fan from back feeding through the system. Set points available are #30102 - 200F on/185F off; #30103 -185F on/170F off.

Ron Francis offers, along with long with preset controls, the Ice Box cooling fan system that has an adjustable operating range of 140 to 230F. It has an A/C request to turn on the fan when the compressor engages.

Along with fixed set points, adjustable controls, A/C triggers and delays, relays for multiple fans are also available. The CD-36 has dual adjustable relays that can keep a cooling fan and electric water pump running after the key is shut off.

Southern Rods adjustable fan thermostat controller is designed to be screwed in place of the drain cock on the radiator with the control switch mounted just about anywhere under the hood. The control allows for infinite adjustment between always running or only coming on at a preset point. Provisions are made to operate when the air-conditioning compressor's clutch is activated. Two different sized senders are available and a 30-amp relay, dedicated circuit breaker and wiring is included.

Preset fan controls are also available. Two different sized senders are available and it comes with a 30-amp relay, dedicated circuit breaker, and all wiring needed.

Vintage Air has several fan controls that have fixed and adjustable set points. They also offer trinary switches that activate the engine-cooling fan when the A/C is switched on.