Ok,
Need some help. I've installed so many amps on so many Fords and all of a sudden, I'm spending 8 hours trying to figure out what is wrong with my new setup. Here's what I've got... 2 10" Sony Xplod 1200 w (330w rated power) 4 ohm speakers in a custom box under the rear bench in my 2003 F150 Sport Extended Cab. I have a Sony Xplod 1000w 2/1 Channel amp (rated at 165w x 2 @4ohms) and 500w x 2 @ 2ohms. The speakers are hooked up normal, not bridged. The problem I'm having is that everytime I turn on my truck, some music comes through but there is an over powering thump thump thump that just goes on and on like a heartbeat (sounds like my speakers are popping). I took the wife's amplifier out of our 2004 Mustang, and when I hooked it up, it did the same thing. I grounded it to the cd player's wiring harness with the wire marked for amplifier ground, the power wire is running through an extra hole in the firewall behind the speedo cluster and into my backseat where the amp is under the passenger seat. The REM wire is connected to the red power wire for the Cd player on the wiring harness. No problems with the powering up of the amplifier. The gain is barely turned up, maybe only 1/4 of the way, sounds terrible. Help Please! I've searched all over this site as I do whenever I have a question, but couldn't find anything!!

 

hmm.. well first off if you grounded the amp on the harness that could be an issue, the ground should be no longer than 12" from the amp. you are fine using that red(swtiched 12 v) but would be better off using the blue/white wire coming from your cd plyer harness.

make sure you have all your rcas running on the opposite side of the car as your power. also make sure they are not pinched. Having installed amps into fords has nothing to do with this. this is a hookup error PM me if ya need some more help.

 

yeah i had the same problem a little while ago, it was my ground wire that came a little loose from all the vibrating. the second time it happened the metal tab where you put the screw through to ground it loosened up on the wire (dont ask me how the hell that happened! )and that was causing the thump thump thump, if its not the ground wire id also check ur RCA's like BLK54 said. hope that helps!

Note: i would definetly consider a different ground besides the harness, find some solid metal to ground it to, and dont make the ground cable too long.

 

Have to agree with the rest of the folks in that you need a better ground, prefereably at least 4 gauge. Also I would power ON the amp from the remote power from the harness, not the switched 12V.

 

sounds like a bad ground to me. Your ground wire should be the same gauge as your power wire to the amp and should be grounded as close to the amp as possible, preferably, to a seat bolt or something similar. Having your remote turn-on wire hooked to your acc. wire ain't the greatest idea in the world either.


regards

 

Thanks for all your help, no doubt, ground wire couldn't handle it. Found a good ground under the passenger seat and bam, that bastard could break glass. Thanks again!