So I noticed this problem when I turned my car on this morning. I have sound coming out of the rear speakers (driven from the head unit), but not the fronts or the subwoofer (each on seperate amplifiers). The system is as follows: Car: 1996 Subaru Legacy Head Unit: Pioneer DEH-7500MP Amplifier (front speakers): older Pioneer Premier 2x100 @ 4ohm amp Subwoofer: Infinity Basslink 1 Wiring: 4ga wire through a fuse from the battery to a fused junction box. 8ga wire from the junction box to the front amp, 8ga wire from the junction box to the basslink. Front amplifier is under the driver's seat, subwoofer is bolted to the back seat, each is grounded seperately to a metal bolt. So I figured I bumped something on the basslink and blew a fuse. The first thing I checked was the fuse at the battery, then the fuses in the junction box. All of those are ok. I used a multimeter to check voltage at the amplifier and subwoofer terminals - both of which come up to about 12.7 V with the car off. Then I pulled the head-unit out to make sure everything is connected. I checked the turn-on wire, which gives resistance between the pioneer harness and the connection on the amplifier of 0.5 ohms. Neither the amplifier or the sub is turning on. Am I missing something, or did the turn-on circuit in my head-unit fail like I'm guessing it did? Any suggestions on other things to test before I buy a new head unit? Cliffs: amp won't turn on. Amp turn-on wire connection is good. Amps are getting power. No fuses are blown. Any suggestions?