Odd electrical issue on stereo power

[mikehhhhhhh]

I have some gauges wired to the old stereo loom that seem to have intermittent power failures.

Sometimes it's just small drops in voltage causing attached devices to restart, others it simply sits at around 1v with ignition on. On one occasion, turning on the heater fan brought power back to the stereo loom.

Certainly some weird gremlins. I wonder if it's a dodgy earth, how is the front of the car earthed? Is it just via chassis or is there a feed somewhere? 

Car is a Honda converted S2 K.

[Escape]

Recently had a similar problem with stereo power on a customers car (non-Lotus). Turned out there was a bad pin in one of the connectors, one of many I must add, going from the vehicle connector to DIN and then to a Pioneer connector. Took me some time to find it, as no load voltage was OK. I'd start from the added gauges and work back to the vehicle wiring loom, carefully checking both power and earth wires/connections.

Filip