1949 Chevrolet

Bluetooth audio, in the dash

• A marine-rated Bluetooth amplifier and speakers: built for heat, damp and vibration.
• Powered from the isolated 12 V house system below, not the car's 6 V side, so the car's ground polarity doesn't matter to it. Fused at the house battery; switched by a relay the 6 V ignition drives (the relay's coil is the only link, and it isolates).
• Hidden in or behind the original dash; the period look stays.

Dual battery: an isolated 12 V house system (decided)

The car stays 6 V, untouched. Beside it, a separate 12 V house system: its own battery, kept up by solar and shore power (a 6 V generator can't feed the usual 12 V DC-DC chargers), with no electrical connection to the 6 V side. It powers the audio, the RF direction-finding gauge, the CAN nodes and logger. Monitored like the others (dual-battery.md).

RF direction finding: a period-styled gauge

A round gauge in the dash, matching the originals, with a needle pointing at the signal. See rf-df.md.

Engine monitoring on a CAN bus (later)

See engine-can.md: a new harness of sensors, CAN nodes, a logger, and ASP suggesting what to try next. Nodes run from the 12 V house side; sensors on the engine are read through isolation (opto-isolated RPM, isolated sender inputs), since the car's 6 V side may be positive ground.

Open questions

• Ground polarity, generator and regulator condition
• Engine (likely a stovebolt six) and carburettor