Double electric fan controls by Dick Ruzzin

DOUBLE ELECTRIC FAN CONTROLS #2/ Dick Ruzzin - 6-01-2006
Panteras have a manual radiator fan switch on the instrument panel. It works fine for turning the fans on ahead of impending traffic snarls, but the constant concern of overheating has led me to install a secondary thermostatically controlled system. This system works independent of the original manual system. You can have both, and happily, the little yellow light in the speedometer goes on whenever the fan is actuated by either system. The thermostat allows the fans to go on and off automatically at a predetermined temperature setting and at the same time the existing manual system maintains the drivers ability to turn the fans on and off whenever it is desired.

I I have two 25 amp electric fans. Since the fan electrical system is critical I used #10 gauge wire, a 50 amp relay and heavy duty wire hardware.

1/ I put a copper pin in place of the fuse in the fuse panel. Then a short piece of 10 gauge wire was added coming out of the fuse holder to a 30 amp circuit breaker with automatic reset. It was installed in place of the fuse. It is the type with bolts and nuts to firmly hold the wires. Clip on wires can lose current if the thermostat heats up.

2/ Wire the thermostatically controlled switch in from the circuit breaker to the fans according to the instructions. The circuit breaker should match the amps required by the fans. Test the system to see if it works before proceeding.
Now at the fuse panel, attach the wire for the manual system to the output side of the circuit breaker. Then attach the other end of the wire from the manual system to a “T” inserted in the wire between the fans and the relay. Both systems are now connected.

You now have two separate electrical systems that are attached at the same source out of the fuse panel and joined together with the hot wire for the fans.

From the fuse panel and circuit breaker I ran the wires down to the floor of the luggage compartment where the fuse panel is, drilled a hole, ran it through a grommet and threaded it through the tunnel area where the water pipes are. I attached it with plastic ties. If you can put the car on a lift this is very easy to do.

Mangustas do not have relays in the fan system so this alone is an improvement. I had a heck of a time finding a 50 amp relay, but finally did on the Internet. I found that the addition of the circuit breaker and 10 gauge wire from the fuse panel through to the fans increased the current to the fans making them run faster and even making the yellow fan light brighter.

After making all the modifications to my cooling system I have so much radiator air flow that the fans now, when not powered, turn fast enough at 70mph to make the fan light glow pretty strongly.

Now your fans will cycle on and off all by themselves. If you choose an adjustable thermostat you can set it for your own driving needs.

There are many types of thermostatic controls in the aftermarket on the internet. I used an adjustable unit from Painless Wiring. It has a probe that you insert into between the radiator fins near the water inlet to sense temperature.They have a great techline that you can call for advice.

Dick Ruzzin
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