Still waiting for engine parts, so have been working on the electrics again. Got this snazzy little voltage dropper off eBay this week. Was about £17 including P&P. It drops a 24-30v supply down to about 12-13v with a peak constant output of 10A. I think it’s designed to power a trucker’s radio, but it will also work for my gauges. Ran the supply via one of the main fuses (previously used to protect the gauges), fed the output back to the fuel and temperature gauges and tucked the unit behind the military dash. Sounds easy, but the whole operation took me about three hours! I shoved my hand into the tank, wiggled the fuel sender and hey presto! The gauge rises quite quickly but falls more slowly. I think it heats a metal strip attached to the needle which expands and contracts. I doubt much current is drawn at any point, but was pleased to see that it pulls maximum current when the tank is full - and therefore empty of air. Not much opportunity for a spark or melted wire in the sender, but it’s good that if there was, it’d be less likely to blow me to Kingdom Come.

Hopefully even The Duke can’t drain a tank of fuel fast enough to beat the gauge!