After 11 years of 914 ownership I've decided to instal a stereo that I can hear. Yes I know music of the engine, bla bla...

Anyway, I'm no electrician but I was thinking I could take switched on power from the fuse panel and run a power relay (similar to the square one used for hot start) then run a hot from the battery and T off the other side of the relay, one to stereo and one to amp. I'll add fuses on after the T.

Does this sound right or should there be 2 relays? what gauge wire should be used for this?

this is where the parallel question comes in. Will I be causing problems for something else by stealing power from the hot side of the fuse pannel?

You don't need a relay. Stereo will have 2 power leads. One of them you run to the fuse panel to an 'always on' source. This is where it's main power comes from. Most stereos don't draw enough power to warrant a relay like you talked about. The other you run to a switched lead that gets power only when the ignition is on (can also be found at the fuse panel). This just tells the stereo when to turn on and off with the ignition, but draws almost no power.

For the amp, run a heavy wire directly to the battery for main power. There will be a 'power on' wire on the amp as well. When this 'power on' wire gets 12V, it will turn on the amplifier. Connect this 'power on' wire to the antenna/amp wire on the stereo (this wire gives +12V when the stereo is turned on and is meant for giving a signal to the amp to turn on and/or the power antenna to go up).

Demick

Nope, sounds right. Make sure you fuse the constant live from the battery BEFORE you go to the relay, not after it.

If more people protected/configured their wiring that way (proper relays & power take-offs), we'd have fewer "Why is it my headlights only go up when I close the passenger door, fasten my seatbelt, and play Def Leppard's YEAH! CD? The only thing I added were some tweeters" questions to troubleshoot.