I installed a 12" JBL awhile back and t-tapped the stock sub signal so i could adjust the volume using the stock dials. Instead of using the remote wire, i wired in a rocker switch so i could manually turn the sub on and off. Now, i have no signal whatsoever to the sub or to any of my rear speakers... I thought they were blown but they pop and work with other amps. Where's the issue?? I took the t-taps out and there's still no signal.

 

This is what i did but i have 2 alpine 12's it works fine. There wouldnt be a fuse for the speakers would there?

 

make sure you didnt tap your rear speakers' positive to a negative and vice verse

also, make sure that the control on the headunit isnt +6 in the front

 

Sounds like you blew the amp mod in the head unit. If you tapped off a sub preamp out it shouldnt have been a problem. But it sounds like you tapped off a powered speaker output and had a ohm miss match that took out the headunits power amp. I would pop out the unit pull the cover off and give a good sniff If it smells burt that is a big clue you did something wrong. Now that you have the wiring back to stock try swapping in a headunit from a friends car if it works you now its in the head unit. Be carefull doing this if you still have a wiring problem you might blow the working one up

 

thanks for the input good heads up on the ohm mismatch, which is what i've concluded the issue is. I rewired the rear speakers from the amp under the driver's seat and got signal back, but it's very weak and almost useless. I took a sniff (good thought) and couldn't noticed a difference on the amp, but since there are separate amps on the head unit amp and the front amp works fine and the rear one doesn't, I'm thinking I need to replace that it. Pulled it apart and couldn't find any issues but... Any other possible ideas on the issue?