A standard yellow one as in the under bonnet fuse box, 4 pins.

Thanks everyone. That makes sense. Would it be a 5 terminal relay or 4?

Oh no, i know where the relay is and I currently pull it out, but it's just not practical to do every day. I'm trying to do the mod not so much for the battery drain but to stop the system emptying the tank and lowering itself to bump stops...

So I'm trying to convert the EAS auto leveling from permanent +12v to Ign. switched +12v to avoid it discharging the battery and the tank trying to do minute adjustments when parked for longer periods. I've seen it described before and involves...