Coolant pump electrical supply

[Chas54]

Coolant system pressure switch ??

I am trying to find why my electrical coolant pump has stopped working and have been testing the two relays (fan & pump)

In the electrical manual , sheet 18 shows the cooling fan wirings but also shows a pressure switch on the 85 terminal of the fan relay , the switch is shown earthed via the no. 4 point .

I cant find this mentioned anywhere else and wondered if it does exist and what its purpose is.

The test i am doing is shorting the cooling fan temp switch to earth to simulate a high temperature (low resistance). With the ignition on the fans will run but the electric pump doesnt start when the ignition is switched off. The coolant pump runs OK on jumpers , the earth is sound. The pump relay operates ok on the bench . The continuity from relay point 87 to the pump supply plug is good.
I am just about to pull the cooling fan relay to check the 12v +ve from the 87A to the C4 pump fuse .

Just wondered if anyone knows about the pressure switch??

[Saltire]

If I remember correctly, the pressure switch is only used on cars with aircon

[Chas54]

Now that makes some sense thanks.

Battery service fuse had blown but i found it the hard way ringing all the wires through from the relay sockets .