Installing a head unit power, but no sound...

[cocojr]

But before anyone tells me to hook the amp cord to the power antenna, I looked in the trunk and it looks like the amp has been taken out. (Bought the car about a week ago but the origional headunit was stolen out) I see the other end of the blue wire in the trunk not hooked up to anything along with about 3 other cables I take it goes to the amp.
where is the amp located incase I'm overlooking it?

and if I'm not...

So how do I get sound?

thanks

[fun2drive]

It sounds like the amp is missing so you do need the amp.
The amp is typically located in the trunk behind the left side panel.
See if it is there and if it is gone then eBay or someplace here in the used parts forum as many guys are parting out good cars.

[cocojr]

So i NEED the amp to have sound? I can't rewire so it doesn't need the amp to play?

Can I replace the amp with a non BMW one...how hard would that be?

[fun2drive]

Yes you need the amp and you can wire in any amp into a BMW but it is not straight forward as in output from HU to amp to speakers equal sound.
Is your HU a BMW HU?
If not then just use an amp you like and wire it like other normal cars.
If you don't have a Bentley manual you need one to see the wiring diagrams which will answer many of your questions.
If you have a BMW HU it is much easier to use a compatable BMW amp.

[TOMNGAI]

check to see fi the amps already bypassed or not. its on the left side of the trunk.

[DINANized3]

Yes you can get sound without an amp but you will need to run new speaker wires to your doors not very hard to do either.The rear speakers will be a little harder to run wires to but not that bad go undre the carpet edge along the door sills .

[cocojr]

The amp itself is gone. I can re run speaker wires to not use the amp? but where would i wire them too?

I think I'm just better off buying a 100$ cd player from bestbuy it let them install for free rather then paying 150$ to get my 140$ cd player installed.

[TOMNGAI]

There are input ( to amp ) and output (to speakers )

if you connected the wires sstraight without the amp, itd probably blow the mid and tweeters.

The guys at bestbuy really arent going to help ( either charge you for more, say they cant do it, or screw it up). youll probably need to get an amp anyway, if you want to run all the speakers. If your cool with just using the front kick panels and the rear speakers, you could just connect the amp in and amp out wires, and make sure to disconnect the ones in the doors.

[DINANized3]

It sounds like you are not very tech saavy you run the new wires from the cd player you put in to the speakers where they are located as to bt pass the amp or like the guy above stated just tie the wires where the amp was together and youll have sound.