First off, is the stereo you're installing the OE equipment or is it aftermarket? It will make a huge difference.

If it's OE Volvo, just match the wires from the head unit to the female plug but I'm guessing that it's aftermarket, so here goes.

"There is a pink wire that says "Memory 12V +" and a black ground wire that comes out of a filter and fuse box."

The pink wire is a constant voltage wire. Test the female connector to see which has constant power (with the key in the off position it should be a pinkish/red wire with a white line). It's for options on the stereo that require memory; clock, stations, etc.

the black is the ground, match it to the ground on the female.

"There is a red wire with a fuse box connected to it that says "12V Plus" and on the stereo this one says to connect to the ignition switch."

This wire is for the power to the speakers. It should only be hot when the ignition is turned to accessory or the on position. On the female plug there should be a bright, solid red wire.

The screw could be a loose connecting screw used to hold the head unit together or a master ground. If there is a woven metal band with an o ring on the end in the stereo dash area, it would connect to that, or it could be the antenna.


Hope this helps.