Daox, thanks for the link to the 12V - 15V converter. I'm thinking about trying that out. I tried my route of connecting a 4V battery in series with the ECU and F/P and F/inj. relays, but that pushed voltage over 17V when fully charged and the relays clicked on and off rapidly. Plus that 4V would be a real pain to recharge relative to my big ol' 12V deep cycle.
On my car these relays are both powered by a "main" fusible link, at 100A. I couldn't isolate any smaller fuses that controlled power to them, strangely enough. They're all fused after the relays, so going by them, the injectors are on a 30A, the ECU on a 10A and the fuel pump is on a 30A. Surely they don't require that much, so it's time to see if my 10A multimeter can handle them. Maybe we can use one DC-DC up converter and a capacitor to power these, as the
vicor converter is only:
12V-15VDC
75W
P/V = I, so 75W/15V = 5A
A fun little FYI, I was checking my math using google as a calculator, and if you put in the units, it gives your answer with units.
amusing.