I have an 85 300TD wagon and Im trying to connect a new 12v power outlet in place of the old ashtray/lighter. (Ive had to get rid of it to make room for a greasecar computer) Ive been getting strange activity coming from the wires that originally plugged into the ashtray assembly.

I simply used the same 2 wires to connect the power outlet but the power turns on and off when I plug something in. I took a reading with a volt meter and it gave me nothing and once in a while when I moved the terminals around the voltage would jump around a bit. The wires are in good shape it seems but Im not sure if they are supposed to be carrying 12v or not.

I did blow a white fuse messing with it. I wondered if anyone could say weather simply connecting some wires directly to the battery and ground, and just fed them through the firewall, if I could use that as a connection for such a power source?

I'm no expert in electronics but would that do the job? of course there would be no fuse attached, but what kind of a risk could I be running? I'd be then using an inverter to plug in electronics for a long car ride but it would only be temporary. I just dont have time to figure out why I'm not getting 12V from the lighter wires.
Thanks
Michael