[V8] Power Port Adaptor Project Complete

urq urq at pacbell.net
Mon Jul 2 15:55:06 EDT 2007

A couple weeks (or more) back I posted that I was working on a project to
add power ports (AKA cigarette lighter outlets) to the V8.  Well, I can now
report that the project is complete and share a few details.  The goal of
the project was to add power ports to the car so that all of the power
adaptors for GPS, cell phones and the like could be used without having them
stick out of one of the existing console lighter sockets ... and without
having to plug in and remove the plugs when getting into and leaving the car
to prevent draining the battery.

I used a 40A Audi relay & socket ... sorry I don't have the P/Ns, I got them
from a starter load reduction relay project I bought from an Audi buddy
years ago ... the relays are standard and can be found in most Audis.  I
also used a Radio Shack 3-outlet cigarette lighter power adapter with surge
suppression; I don't see it in the current on line catalog.  Rather than
hacking the adapter, I installed a cigarette lighter socket under the
console (also obtained at Radio Shack), so I can remove the adapter intact.
I tapped power from the wire going to the cigarette lighter plug on the
console, installed an inline fuse holder, then to the relay contacts and the
power socket.  I ran a ground wire up the tunnel to the firewall and over to
one of the ground lugs under the passenger's footwell.  The power wire for
the relay coil is also run along the top of the tranny tunnel to the fire
wall and down into the relay box under the passenger's footwell.  

The relay coil is powered by the circuit that supplies power to the windows
and sunroof.  I chose this partly because I found a convenient tap in point
and partly because it will allow the outlets to remain powered up after the
ignition is shut off but the front doors are not opened.  There's a 0.5mm
Red/Blk wire that goes from pin T8c/8/87 on the power window sunroof control
unit to pin 6/85 of the comfort relay.  This particular wire may only be
found on '91 and on models, but it is the same circuit that goes to all the
window switches as a red/black wire.  The plug for the adapter is inside the
console and I ran the cable along the left side of the console, exiting at
the end of the carpeted plastic cover on the left side of the console.  

All in all it worked out quite well.  I've got photos of the assemblies and
will be turning this note into a web page as I have a chance.  If anyone has
any questions or would like more details, don't hesitate to ask!

Steve B
San José, CA (USA)

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