I have begun work on the electrical subsystems. The 12v will be handled by a Iota 55Amp 96 – 190vdc DC/DC converter, along with a small auxiliary battery to power the initial contactor activation to switch the traction circuit on.

I’ve also begun etching the new battery rack/motor mount for coating with POR-15. I am also creating a new front wiring harness. I upgraded the original setup which routed the headlight power through the physical switch in the steering wheel, with a pair of relays switching straight to the 12v system’s battery. This should bring the voltage at the bulbs from the ~11.5 volts it was previously up to 13.6 volts from the dc/dc. I’ve heard this makes a significant difference with the dim old headlights of this 38 year old vehicle, as well as removing the biggest strain on the aging wiring. All front headlight and side marker connectors were replaced with OEM grade dual gasketed weather pak connectors.

I’m also etching the front and rear battery rack components. Also shown here is the contactor brackets made from 1/8″ steel flat stock.

I also fabricated a proper foot controlled throttle using a 25k potentiometer. This worked out so that the ~70* of mechanical throw from the original throttle setup became a steady linear range of 0 ohms through 5k ohms. A spring provides positive return and a very nice amount of pedal resistance.

I set up forced air cooling for the kostov motor. An automotive blower provides several hundred CFM of airflow through the motor. It was oriented as to swirl through the brushes before exiting the motor. Testing shows that even after several minutes of acceleration with many huge amp draws through the motor (600+ amps)the exhaust air was only warm, and the case barely warm to the touch. The blower draws approximently 10 Amps free air and 6 Amps when installed blowing through the motor.

The cooling setup is not finished. I must still create an end shroud for the motor to force more air to pass through the body of the motor.