Charge cooler water pump fuse/relay Options

[rhodesyboy]

Hi basically I am struggling with my water pump for the charge cooler and I'm just doing voltage checks to see whats what.

Basically what I have found is that at the relay there is no voltage from the ECU for the magnet side of the relay, even when I give it a good rev there is no voltage across the two slots with the relay taken out.

Then for the slot that should supply the voltage to the pump is only getting 7 volts, so I then went to the CDS fuse and unplugged it to try and get a voltage but when I unplugged it there was no voltage at the pins and obviously none at the relay but then when I plugged it back in it all came back.
I did check there is continuity across the fuse, is there any point checking for resistance in this fuse? If so how much?

So has anybody got an idea or experienced this kind of problem?

Also I am checking it right aren't I, taking the fuse or relay out and probing where it should plug in and checking the potential difference (voltage) across?