Hope someone can help with this.
Battery sometimes goes flat overnight.
Jump start with a booster pack doesnt take much to make it start and all will be fine for the day and maybe a couple, but after a night or two back to the fllat battery.
New battery bought at xmas, alternator putting out about 14V.

Now two POSSIBLE causes
1/ when sitting stationary with car running, if I operate something reasonably high current draw, lights heater fan, electric windows etc the speedo needle jumps up (about 20mph) then goes straight back down, when driving seems ok with no fluctuation.

2/ When jumping with the pack as soon as the car starts the fans radiator fans kick in for a few seconds, also seems like they run at a fast speed for say 5 secs then a slower speed for a few more secs before stopping. Had it on my old Cos that the radiator fan switch controlling the fans failed and that used to bring the fans on at night and flatten the battery, so wonder if anyone had the same problem on a mondeo and also can the fans run at different speeds and how are they controlled.

Any pointers appreciated

Cheers

Steve