(1 for the vacuum pump for the brakes and 1 to disconnect the PSU/DC-DC convertor when the ignition is switched off as this causes the 12v battery to drain to overnight.)
And to get the EMW charger testing completed, get the charger working and charge the 3rd (Front) battery box.
It was my dad’s 70th birthday this last weekend so Saturday evening was already booked.
I spent most of Saturday morning working out how to use 12V automotive relays and fitting both the rear PSU/DC-DC convertor cut off relay and the front vacuum assist brake pump relay, wiring it through the vacuum sensor.
I tested it by wiring the relay direct to 12V switching on the relay permanently and adjusting the vacuum sensor sensitivity down until it settled a little.
I may need to service the vacuum pump or the vacuum chamber on the car as it did not seem to hold the vacuum for very long before the sensor detected a drop in vacuum pressure and kicked on the pump again, however it did definitely respond to me pressing the brake pedal as expected and refreshing the vacuum ready for the next push. Great :-)
So all I have left to do here is find an 12V ignition wire somewhere near the front of the car and route it to the positive input on the relay so the vacuum pump only runs when the ignition is on.
However there was never a need for 12V ignition in the front of this rear wheel mid-engine beauty, so I will need to go hunting under the dashboard for an ignition feed to finish this.
The car is booked in to the mechanics to have its final fix before MOT on Tuesday of this week (24th) Brent just needs to make a battery tray from some angle iron for the 12V Battery and fix all the HV cabling to the body proper as it is just secured to brake pipes at the moment with zip ties.
So Sunday morning I got down to charger testing.