User Manual

INSTALLATION

REDARC strongly recommends that the probe be installed in the radiator by a suitably

qualiﬁ ed radiator specialist.

1. Allow the engine to cool completely before commencing any work on the radiator.

2. Select the position on the radiator header tank for the lowest safe coolant level (the point where

alarm is to sound).

3. Drain coolant (to at least below the probe mounting point).

4. Drill and mount the coolant level probe, taking care to avoid any drilling swarf entering cooling

system:

• For a metal tank, solder in the threaded brass boss. When cool, screw the probe in using thread

tape.

• For a plastic tank, thread the hole then screw the probe in using thread tape.

5. Reﬁ ll the cooling system.

6. Mount the LCA1224 where it can be seen and heard from the driving position (or use external

warnings, see below).

7. Connect the wires. (Refer to diagram on next page)

The external warning outputs (YELLOW & GREEN wires) are GROUND outputs, so the other terminal of the

lamp or buzzer must be connected to BATTERY POSITIVE. The warning lamp may be a LED with a suitable

series resistor or a ﬁ lament lamp. The maximum load on these wires must not exceed 0.5A. To operate

higher loads (either output), use the wire to operate an external relay.

INSTALLATION NOTES

The LCA1224 relies on the probe getting good conduction to ground through the coolant. In some cases,

after installation, there may be an alarm even if there is plenty of coolant. This can be caused by:

• The probe being placed in a plastic expansion tank with a long pressurised joining tube to the

radiator making too long a conduction path through the coolant.

• Even a short joining tube having a bubble or air-lock preventing the probe getting conduction to

ground through the coolant.

In these cases, it will be necessary to add an earthing probe into the coolant at the same level as or

below the LCA1224 probe. This does not need to be the same type of probe. It can be a stainless steel

bolt (with suitable nuts, washers and sealant) connected with a wire to chassis earth. (Insert the bolt from

inside the tank with the threaded end outside, to allow connection of the earth wire lug). It is important to

ensure that the probes are sealed and secure and do not allow any coolant leakage under the heat and

pressure of the coolant system..

In all cases, it is essential to ensure that the level sensing probe(s) are placed in:

• The pressurised system and not in a non-pressurised overﬂ ow or expansion capture bottle (these

usually have a simple clip-on or screw-on plastic lid instead of a pressure cap).

• Part of the system that will empty rapidly in the event of a sudden loss of coolant. Consider, for

example, if the chosen expansion tank has a long, narrow connecting tube to the radiator that may

slow the emptying of the tank and delay the alarm with costly results.