[CamaroBruno]

Thanks for the input, gents.

Originally Posted by ctrlz

This sounds like a battery charging problem. Your display is reading 13V, so I don't think you have a dead cell in the battery (would be give you like 10-11 V). If you jump the car from another running car, it should start up, unless you have crappy clamp connections to your battery cables and they are not passing enough current (amps).

You need good connections to your battery posts to crank the car. Loose connections will run the accessories and lights, but you need amperage to turn the starter.

At face value, that 13V reading would indicate a fully charged battery. I would see if either of the battery post clamps are loose. Then disconnect and clean them up prior to reconnecting. If you got it partially cranking with a jump start earlier, none of what I suggested about fuses and relays is the likely problem. You are just not getting enough power to your starter.

This is possible. Batteries can fail in strange ways.