This alarm can be fitted to any vehicle that has a plastic header tank and is 12 Volt negative ground (24 Volt alarm is also available Click Here )

The circuit works by the coolant conducting electricity through it, and holding the alarm off.
The circuit is from one screw through the coolant to the other screw.
No coolant means no flow of electricity and the alarm switches on.

This alarm is supplied with a 120mm long top screw this is suitable for the standard Mazda Bongo header tank.

If you have a different vehicle you may need a different length top screw.

You will then need to measure your header tank to get the correct length.

We stock 60, 70, 80, 90, 100 and 110mm long screws.

We have other alarms listed on eBay with these screw lengths included.

If your header tank is metal It can also be used with a float switch (see bottom of tet)

The LED is a flashing type clear transparent when off.

Sensor wires are 2.2 Metres long.

Ring terminals crimped on sensor wires and stainless steel self-tapping screws.

Ring terminal on ground wire.

The new circuit is smaller and is covered with a self-adhesive pad that insulates from being shorted to any metal parts,

and can be used to attach it to any convenient flat clean surface.

General Fitting Instructions.

This alarm has two white sensor wires and it is important
that the plain white wire is fitted on the top of the
header tank and the wire with the black stripe fitted on the side.
The red and black wires are the power wires, the black wire should be
screwed to any nearby grounded metal, and the red wire fitted
to any fused circuit switched on by the ignition key using the lowest
current fuse that is available.
If there is no spare fuse the red wire can be spliced into an
eisting circuit as it uses very little current even when the alarm sounds.

When fitting the long top screw into a Mazda Bongo header tank.
Care should be taken to avoid the vertical baffle plates that crisscross the tank,
they show as squares when viewed from the top.
The long screw is fitted in the top of the tank as close to the tank centre as possible.
If the screw is not started completely vertical it may hit one of the plates
by the time it reaches the full depth.
If the screw tip hit a baffle plate this would stop the alarm from working.
The right side of the tank should also be avoided as it is not deep enough to take the long screw.
The bottom screw should be fitted in any convenient position well below the tip of the top screw.

We have supplied two square plastic spacers that should be fitted as shown in drawing 2.
They need to be drilled in the centre the same size as the header tank holes 2.5mm
Then screwed onto each screw after the ring terminals, because they are forming
threads you will need to hold the spacers with pliers or in a vice, make sure they are
about 20mm along the screw before screwing into the tank, so that they do not
contact the tank until well after the tank thread has been fully formed.
You will probably need to use an electric screw driver on the screws, this should be
done at the lowest speed possible.
If screws are driven quickly it will heat and even melt the plastic of the tank.
The spacers are used because the screw threads do not go completely to the
head of the screw and this would be where they are most needed as the screw is
tightened onto the tank. The spacers make sure that good threads are in the hole as
the screw goes tight. It also means that if you were to over tighten the screw it
would have to strip the spacer thread and the tank thread before failure.
Do not over tighten the screws, only one customer (out of about 3000) has ever reported a leak.
If there was any sign of a leak:-
just loosen the screw about 10mm and put silicone sealant around
threads and between the spacer and the tank then tighten again.
Do not put sealant on the ring terminal or the head of the screw.

I will be happy to answer any questions promptly either via eBay messages

Drill bits needed:-

2.5mm for header tank screws
5mm for LED or 7.5mm if the supplied bezel is used.
7mm for test switch

This alarm will also work with most float switches and without any changes.

Most float switches have the option of N/C or N/O contacts, The sensor wires are connected to the N/C pair.
Some are N/C only and can be used.
Some are N/O only and cannot be used.
N/C means:- Normally closed contacts.
N/O means:- Normally open contacts.

Low Coolant Level Alarm Mazda Bongo 12V Buzzer & LED .......120mm Screw...