voltage

hi all, new here and i have absolutely no clue when it comes to cars so just looking for some help please. i have a 56 plate ibiza 1.4l petrol with about 87,000 miles (i think thats all the relevant information) im having a number of issues with my car which is making me quite scared to drive...

Does anybody else get just over 8v down the Brake light feed wire when the tail lights are switched on, but the brake pedal is not pressed??? goes to normal voltage when brake pedal pressed, and back to just over 8v when brake pedal is released, but to 0 volts when the tail lights are off...

anyone know how i can measure the alternator output voltage? haven't got a multimeter but have got vagcom anyone know how i can do this with vagcom?

Hey Folks, Got the following error on VAG-COM: Address 09 ------------------------------------------------------- Controller: 6Q1 937 049 D Component: 0000 BN-SG. 1S34 Coding: 16396 Shop #: WSC 06402 1 Faults Found: 01598 - Drive Battery Voltage...

Fitted this yesterday, went for the cheapo option, a TIM white face, got it off Demon Twerps 25 notes for the gauge and 7 for the mounting bracket. My frugalness backfired however, when it arrived there were zero instructions and only about 4 inches of wire!, however it did come with the option...