Polo struggling with 2 amps?

[Lakey]

Wasn't sure whether to put this in ICE or Electricals, but anyways...

I have been running 1 amp for quite a while now, powering a sub. With just the stock speakers in the front, things were sounding pretty shabby. My passengers also complained that there were no speakers in the back.
I decided it was time for another amp and a pair of 6x9s (Yes I know they suck, no need to mention it. They are cheap and easy to fit, end of).

I now have 2 amps in my boot, both are the same, and only 500W max. Here's the exact one if it helps:
http://www.caraudiodiscount.com/ja490-5 ... 11473.html

Anyway, just took the car for a spin to see how it was all sounding. I went about 50 miles in total, then when I pulled back into the driveway and stopped my battery warning light came on, and I lost a lot of power (headunit backlight switched off for a second, headlights dipped). Obviously throughout the journey I was running my headunit, the two amps, and then just the usuals - headlights and heater.

Right now it's dark, and pretty late, so I'm not messing about with it, I will wait until tomorrow. Just wondering if anyone has any suggestions to what I should be expecting. Dodgy alternator? Dieing battery? I really havn't a clue, I'm not technically minded.

I will just add one more thing; The amps are definitely wired correctly.

Thanks.

[Tim_GTi]

What's your setup up plan? Like what amps are running to what, and from what, where are they fused etc....?

Could be a dying alternator or battery, most likely the battery. When was it last changed if at all?

[Lakey]

Well rather than rip the wiring for the first sub out and replace it with uprated cable and a distribution block to run both amps, I just ran another set of cables. So both are wired in the same way:
Power cable down passenger side, fused at battery end. Then the subs contain fuses so I didn't bother with any at the other end.
RCA leads from headunit run down the drivers side.
2 separate remote wires, one switched, to turn the sub on and off.

Neither the alternator or the battery have ever been changed (or so the previous owner tells me anyway) and the car is now 7 years old.

I've just thought of something that happened the other day as well...
When I opened the door the interior light came on as it should, but as soon as I started the engine it was flickering like crazy. This was before I had turned the headunit or anything else on.

[Tim_GTi]

Sounds like you've got an unstable and unefficient system, and it's knackered your battery.

You should have done:

Live lead to fuse block in engine bay
Fuse block from bay to distribtion block in boot
Distribution block running two fuses, one for each amp. Live leads lead from here to the amps.
Ground cable for each amp. Your could've bridged one here but best to have one for each.
Remote cable from headunit to speaker amp. remote cable from speaker amp to sub amp.
RCA cables on opposite side of the car from power lead from headunit to each amp.
Speaker and sub wiring accordingly.
All relevant crimps and connectors.

Not doing any of the above could lead the system to not shut down properly after the ignition is off (bad remote), surged the system (not live), not worked at all (bad earth).

I'd recommend re-seeting up your system so it's running properly and safetly, and get your battery tested to see if it's charging and powering properly.

[Lakey]

Been using the car today and everything was fine, no sign of the battery being flat or anything.

I am short on cash at the moment, that's the reason I wired things the way I did. I just used the wiring kits that came with the amps.

To get everything wired up as it should is gonna set me back at least £50, and I've got to fork out for a holiday and a leeds festival ticket this month. Plus, I owe my mother £380. Bad times!

I will definitely get the battery checked though.

Thanks for the advice Tim!