Fronts Stopped Working

[MrNutter]

I replaced my old Sony 4ch amp with a new one because the old one died. They are virtually identical so I used the existing wiring. I also upgraded my front speakers to a set of 6.5" Clarion components & moved the Sony components from the front doors to the parcel shelf next to my 6x9's. I used the Clarion harness up front & moved the Sony harness to the parcel shelf. Other than that all the wiring is the same as what it has been for a couple of years. Only the sub & fronts run off the amp.

Turned it on & it was all working. Crawled into the back to set my gains & did the fronts. As soon as I started to turn the dial for the sub the front speakers died totally. Checked the fuses & they are fine. Switched the RCA leads over & had no fronts & no sub. Wired the fronts to the subs side & the sub to the fronts side, left the RCA's alone & the fronts worked but no sub. Left the speakers wired as they were & switched the RCA's over & had a sub but no fronts. So both sets of RCA's seem to work & all 4 channels on the amp seem to work but it depends on the combinations as to what wants to work when. There's no combination where it's all working. I originally thought that I might have killed one of the RCA outputs on the HU but both sets of RCA's seem to work so that doesn't seem to be the case. Thought the amp might have been the problem but all 4 channels seem to work depending what's hooked up to them, so that doesn't seem to be the case either.

Anyone got any clues what this might be, I'm stumped.
Thanks for reading & thanks for any replies.

[HCVP]

I might be completely wrong, but if you connect an amplifier to your head units pre-out channels, then you are bypassing that channels in-built amplifier. It's either one or the other.

To confirm this just connect both the front and rear pre-outs of your head unit to your amplifiers 4 channel inputs, and wire up 4 of your full range speakers.

[MrNutter]

Thanks for the reply HCVP. I borrowed an identical amp off a mate & wired it in to test. It was acting the same way so I ruled that out. I put my old HU back in & hey presto, it's all good again. Must have fried one of the pre-outs I guess. I'll leave the old deck in it until I can afford another new (& better deck).