1985 porsche 911 headunit

Have anyone installed an aftermarket unit on any type Porsche 911 1988 and earlier model? I have installed a unit to the correct cars factory wires, also checked the wiring diagrams here at this site for the car and unit. All checks okay but the unit looses its memory once the car key is turn to the off position. I was thinking to re-route the accessorie wire to a constant power source like the clock or the lighter in order to preserve the memory once the car is turned off. The Pioneer unit does not have a independent memory wire like most other units, it is just red power (battery) and yellow (acc). Besides that there is the one to the antenna but that's it. Does anyone has any suggestions on this? Thanks!

hi,

if the unit you installed is a high power unit, it would be just as easy to bring a wire through the firewall and connect it to the fusebox on the driver's side of the trunk.  there should be a milky white plug (1/2 inch or so in diameter) to the right of the radio, behind the glovebox area.  you can use that plug as a hole (grommet) through the firewall.  at the fuse panel, the fuses toward the rear of the car are constant power.   hope this helps.

mark

You know what Mark, I think you got something here. I did saw some plugs (grommets) on the back of the firewall when I de-installed the original radio. The access to the main fuse panel from there is easy, I think that running a wire to it should be fine and clean. So, on this case running the red wire on the head-unit which is for accessories should be fine. What you'll think?

check your wiring for the headunit as tcss suggested, red is usually switched power, yellow constant.....although way old pioneer's used orange for constant and red for switched.  make sure to use the same gauge or slightly bigger wire for the connection.  and i'm pretty sure the top row side of the fusebox is the hot (unfused) side.  if you tap in there, may want to add an additional fuse.  or use the cold side of the fuse box. 

mark