[Mgs] Battery/Alternator question (Non-MG)

[PaulHunt73]

Could be all sorts.  Measuring the voltage of a battery off-load doesn't 
really tell you much, although 12 plus immediately after a failed crank 
actually indicates the battery is probably OK, although it could be 
intermittent.  If it happens again put the meter on the battery posts (not 
the clamps) while trying to crank, then on the clamps, then on the body and 
the starter solenoid stud, then on the engine block and the solenoid stud. 
If any of them show very low voltage then the problem lies back towards the 
battery.  If the battery posts show that then the battery *is* knackered. 
Wherever you see 12v or nearly so the problem lies forwards to the starter. 
If you see 12v on the block and the solenoid stud then the problem is in the 
solenoid or starter.  If you see 12v at one test point, but very low voltage 
at the next, then the fault lies between them.

Remember you are testing two connections each time, so if, for example, the 
battery posts are OK but the clamps aren't then it could be either of the 
clamps, so you need to test between one post and the other clamp, then the 
other way round to see which clamp is at fault.  Or simply take both off and 
clean them.

This isn't exhaustive, there could be a bad connection between the earth 
cable and either the clamp or the lug, ditto the battery cable.  You could 
also have more than one fault.

PaulH.

----- Original Message ----- 
> This morning my non-MG vehicle (1993 Volvo 240) wouldn't start. It cranked 
> a
> couple of times and then died. I measured 12+ volts at the battery.