’94 aerostar premium stereo

I just put a Pioneer am/fm/cd into a 1994 Ford Aerostar van with a premium sound system. I replaced the front dash and rear 1/4 panel speakers, and the rear speakers seem to have no volume compared to the front. I've played with the fader control and made sure the FIE on the Pioneer unit is off, but the front is still much louder and brighter than the rear. The OEM system was an am/fm/cass with 6 speakers and headphone jack/volume controls for the rear passengers. I removed the rear lifgate speakers and am running just 4 speakers in the system. Would the way the rear system with the headphone controls is wired be affecting my rear speaker output? I was considering running new lines to the 1/4 panel speakers and bypassing the OEM wiring. Does anyone know if this is the best way to go, or is there a better way to tackle it?

Thanks,

Dean.

these are fun to do run all new wires have fun..

I figured the headphone jack was the problem. I remembered something about it being an issue with Aerostars and Explorers, but couldn't remember what the best solution was. Thanks for the help! Off to run new wires I go!