Audio Systems: remote turn-on lead, loud thump, dimmer circuit

Question
Am installing an amp and powered sub in my '99 s-10 pickup with aftermarket Jensen head.  As far as the wiring goes I've fingered the B+ and accessory wire from the original harness and have only one semi hot lead left; it's a grn wire and hot with ignition on but dead in the accessory mode. Is this OK for the REM for the amp and sub? Also there's two remaining wires that I can't figure out: One is gray, the other purp/wht. They don't give a voltage reading.  Thanks. Matt.  

Answer
there's a page here:

http://www.installdr.com/InstallDocs/GM/PDF/460001.pdf

that shows information related to this vehicle.  Although they dont seem to match what you're finding.  the gray one may be the light's dimmer circuit and the purple may be for a power antenna.  if you dont have these features they may just be dead unused wires and you can just tape them up and forget about them.  As for the wire that's only hot in the on position, you could use this to trigger the amp but the head unit (since you installed an after market unit) should have a wire specific for this, it's usually blue, sometimes has a white stripe on the blue?  sometimes it will even be tagged as remote or at least "REM".  see if that's there and if so, use that. if not go ahead and use the wire from the car but remember that your amp will be on even when the stereo isnt and sometimes this can cause a loud THUMP when you turn the stereo on or off.
Maybe keep the gain on the amp down until you find out there's no thump.

Good luck!