There is a 40 amp fuse for the OEM amp. I don't believe it pulls anything close to that. The wiring on that circuit is 14 awg at best. I know I tried to power my new amp using that circuit , just to see. No good. The amp must have been getting quite a voltage drop across that small wire because the performance suffered considerably. I ran separate or new power and speaker wires for my installation. I did use that 40 amp circuit for the trigger to turn on the new amp though.