s650 cranks 1 sec and goes off line

[Dmo]

My S650 on cold weather start will crank for 1 sec and goes off line, all power off. Do start sequence over and same thing. all battery cables and clamps clean and in good shape. Starts good when warm. block heater is plugged in and works. Any ideas?

 

[Phil314]

My guess would be the battery is weak. You could try hooking up a jump pac and see if it does the same. Or you could have it load tested.
Personally if the battery was older, I'd just replace it. Newer equipment is sensitive to voltage and a weak battery can cause all sorts of weird issues.

 

[foton]

remember when you get it started to check alternator for good charging voltage (around 14.2 volts). that might be why battery is weak.