I've just put a voltmeter across the battery of my car, whilst the engine was running and it read 30v.

Is this normal??

I want to install my Kenwood TV headunit and two amps, but won't the higher voltage blow them up?

My car is a Jap import. My apologies if this has already been posted.

 

If your car is running on 30v, stop now, disconnect the battery before you knacker everything from the ECU downwards and call a specialist. If it is running at 30v, bulbs would be blowing and almost every electrical system would be in pain.

you should *never* see 30v. Even if your regulator is knackered, it should still only make up to 20v.

I'm guessing your multimeter might be knackered, but if you're confident that it's really 30v get it sorted right now, immediately, if not sooner.