[pampadori]

you can test your ground strap. Here's how:
- check voltage at battery while engine is running and value is low
- use a set of jumper cables as additional ground path by clamping one end to the engine (metal part of course) and the other end to the chassis (also to metal).
- recheck the voltage at the battery not that you have added an additional ground circuit path.

if the voltage is higher, you likely have too much resistance in the ground strap and need to replace it.