central grounding

Ok I ve got an old mercury in my bay, I have tested an the speakers pulse but they apparently have only 1 ground for the front and 1 for the back,. I have not installed a head unit in a situation like this ever, can I install new alpine in  this car by connecting the grounds together or do I have to re-string new speaker wire in this car?

Unfortunately, you will have to run all new speaker wire. I had this problem in my '85 and '86 300ZX's. I'm not sure whether you would have to swap the speakers as well (don't think so), but I did in my car anyways (already planned to swap the stock speakers with components).5.25" Components & 5x7 Coax Kappas w/Power Acoustik OV4-800

KAC 7252 powering 2 D3 8" Diamonds

KDC-MP728, KGC-4042A

Ya I figured this out, it needed new speakers sadly enough the car was not worth even a new cd player much less new speakers.

hey just because the car is a beater doesnt mean it doesnt deserve an audio upgrade. lol. I was thinking about buying an old '94 cavalier wagon and putting 10 subs in it a a crapload of component speakers. granted they were going to be mostly low end stuff, but it still would have sounded somewhat decent. Its always whats on the inside that counts. lol"People with mullets live 40% longer"   - Ricky Bobby

I realize beauty is in the eye of the beholder, but it was ultimately the customers decision on whether or not he wanted to spend the money to install new speakerscd player/wires+labor on this rig. He ended up appreciating my decision in not installing new equipment, he also liked my idea about a demolition derby for his car, haha!