The installation of your coolant pump is beyond the scope of this document, however, here are some basic considerations.

• There should be no thermostat installed, the electric coolant pumps are most efficient when allowed to run with no restrictions.
• This controller must be the only device connected to the temperature sensing thermistor.
• The thermistor should be placed as close as possible to the coolant output (upper radiator hose) of the engine.
• The battery must be disconnected while making electrical connections to the controller and other devices.

The following wiring diagram shows how to connect the pump and controller.

Equipment List:

• This Coolant Pump Controller
• 12V relay capable of running the coolant pump
• 12V coolant pump
• 10kOhm at 200F thermistor
• Optional 12V (<250mA) warning lamp

The controller is not weather resistant and needs to be installed in the cockpit, preferably in a place that the driver can see the LED’s. The connectors on the controller are screw-clamps and work best with just bare wire.

Calibration:

This controller is designed to manage the temperature of the engine by switching between two control modes: Pulsing and On. The temperature of the change-over is adjustable. The characteristics of the pulse are also adjustable. There are LED indicator lights, Green to indicate power, Blue is for the pump and Red is for the thermistor wiring warning.

The adjustment of the Pulse has two elements, the On-time and the Off-time. The On-time is used to stir the coolant to prevent hot spots while the engine warms up. The Off-time is when the engine actually warms up. The setting for the On-time should only need to be adjusted once. Use V10 (12 turns) to adjust this setting. This timing should allow the pump to come up to full speed, then stop immediately, there should be very little movement of the coolant. During warm-up, the coolant in the radiator should stay in the radiator. A 150 liter/min. pump will transfer the entire contents of a radiator in 3 or 4 seconds. There is no hole in the housing to make this adjustment.

The next setting is the Off-time (V7 – 1 turn). This is the time that the engine is actually warming up. This setting may need to change, depending on ambient conditions. There is a hole in the housing to accommodate this adjustment. We’ve found that a setting between 4 and 8 seconds is enough to keep the engine warm when the ambient temperature is above 50F. This may be different for your particular configuration.

Now that the engine can warm-up, the temperature set point needs to be adjusted. With the controller installed, start the engine and let it warm up. Adjust V1 (12 turns) to change the temperature that the pump changes from Pulse mode to On mode, this will determine the operating temperature of the engine. The other adjustment (V2 – 1 turn) is the transition temperature from On mode to Pulse mode, most of the time, this setting should be left as high as possible. Adjusting V1 will change the set point of V2, however, adjusting V2 will not change the V1 setting.

Time for a test drive, make sure that the engine stays warm with air moving through the radiator, adjust V7 as needed. There is a hole in the housing for this setting.