Charged the battery last night, don’t know to how much other than 11.8v coming off the terminals according to the multimeter.
Today, I’ve put the coolant system back together as the new parts aren’t coming until Tuesday, this way I can check that the inlet manifold repair is good.
Battery wasn’t dead, central locking unlocked this morning, good news. But must be draining somewhere, but again I don’t know how charged it was last night as couldn’t attempt to start it without an intact cooling system.
So, coolant back, booster pack on, turn key = vroom. Voltage off alternator terminals = 13.8V, pretty constant even with revs, same voltage at battery when motor running. Ran it long enough to get coolant+flush stuff hot, good news, no sign of water leak from inlet manifold
Bad news, battery dead, I mean not enough to turn starter. Have I just been unlucky and have a short-life battery and all the other things masking it? Would a short somewhere show in some way with the multimeter. I’m going to now remove the new electrical stuff, the subwoofer and unplug the stereo ISO leads, and then try again. I kept my last battery as I wasn’t 100% sure it was dead, that has the battery charger on it at the moment.
Before I put the steel toe caps on and play football with the car in frustration, any ideas?