Volvo: Getting it started..., volvo 740 gle, gauge wire

Question
I have a 1987 Volvo 740 GLE (non-turbo). Someone had put a subwoofer set in the car. I think that's why it's down now. They had a gauge wire on the hot terminal of the battery. It turns but does not start. It's not the fuel pumps or the relay, I have a new coil, distributor, ECU, & a new set of spark plugs. I even replaced the power stage. What else could it be? Could it be a bad pick up? Please help me.

Answer
Hi Drew,first disconnect this extra cable,do you have a spark?,there are only 3 essential things that this motor needs,air fuel and spark,if you are sure about the fuel then the spark is only thing left to check,if you do not have spark i would guess either the sensor in the distributor or the ignition amplifier which is located inside the left front fender(behind the air filter box)