Join Date: Feb 2016
Location: Adelaide, South Australia
Assuming both bike and car/truck have 12v systems then both will have very similar running/not running DC voltages, when running both around 14v, not running both around 12.8v, assuming batteries are ok. Assuming no faults with the bike it will draw what current it needs for the starter motor, fuel pump ecu etc. if there is a fault with the bike the car battery will deliver more fault current wether the car is running or not. Alternator outputs these days are well regulated, ie output voltage won’t change much more than a few hundred millivolts idling or revving.
Can we assume the bike was disconnected from the car after the bike was started and then it ran poorly/stalled, if so then probably failed bike battery,
2017xt 650 vstrom, yellow.
Ohlins SU216 rear shock, .85 fork springs, cogent DDC, Barret 3/4 exhaust, 20mm rear raising links, ricks fork brace, oxford heated grips, Radguard, Altrider bash plate & engine bars, Steel pony soft panniers and rack, TAG bars, foot peg lowering brackets, gear lever extension, bar end mirrors.