i have my red and yellow wire going to proper wires on a 94 civic. except nothing works. no power or sound. so when i connect all four wires it works. but my clock and radio still get reseted. suggestions?

 

Your "back-up" fuse is blown, it is in the engine bay fuse box, probably a 7.5A, [hot at all times].
Your aftermarket HU is "high powered" the stock constant power is not enough to power the HU.
Run a fused 12ga power lead from the batt. to behind the HU and connect the HUs constant power, [yellow] to it, don't forget to cap off the stock constant power, [and replace the fuse].
You will also need to add a 12ga ground from chassis of the HU to the cars chassis, if you use a metal "L" bracket off the back of the HU to the stock rear support brace, [where stock HU was mounted] you will not need the 12ga chassis to chassis ground. 94

 

so connect the units red to the cars red but run a 12ga wire from batt and connect the yellow. and ground the units black to the chassis?

 

Yes. 94

 

problem solved! thanks!