After getting the motor back on I was wanting some more instruments. I ordered this circuit from ZEVA in Australia some time ago that is specifically for driving normal car gauges. I used an existing bolt hole to mount the circuit.
It took me about an hour to find the best spot taking into account that it needed to be away from any splashes, need to be able to access the trimmers to adjust the settings and be able to pass the main power cable through the sensor. I also needed to provide a 12v supply to the circuit and feeds for the gauges.
The circuit is the plus version that drives the car fuel gauge, but this plus version also drives the rev counter showing Amps x 100, so my rev counter was reading 0 to 800 amps. So far I've only hit 700 Amps for a fraction of a second.
The photos show the circuit, the mounting position and it's location in the car respectively. It is behind the main connector and one of the headlamps. The area was dry and it has been raining hard recently, so it is all good. I shall make a cover for it as well. The rev counter works really well and reads a little bit lower than the JLD 404, but the fuel gauge doesn't work in a linear way. That may be because the original fuel gauge sender was perhaps logarithmic instead of linear so what I get is the gauge, when full, drops very quickly at first and slows down as more capacity is used. It will take some getting used to, but I Like the idea of a simple gauge to check capacity so I can monitor overall voltage on the JLD 404 and eventually on the battery monitor circuit. That's one of my next jobs, to connect the battery monitor circuit back up so I can view groups of 4 batteries, then add some more analogue measurement boards to give me all 38 batteries. At least now all the batteries are together in the trunk, so wiring them all in will be easier. Then a posh cover for the batteries to top off the trunk.