[levdeb]

So our 2006 Cayenne S doesn't like to start. The battery is 100% charged. Hop in, turn the key, and it just clicks, lights all go out, and then locks the key in the ignition. Hook up the voltmeter, and there is at least 15v... Hook up the battery pack to jump start, and it fires right up... every time.

I've (in the past) tried using a battery cut off switch, replaced the cables, replaced the battery, and more. Now I am starting to hear about where the cable goes thru the firewall to the starter being a potential problem. I can't find any diagram to show where this is. I'd like to do some sort of continuity check from the inside to the engine bay.

Again, plenty of power on the engine side of the firewall. Seems like the power is being lost from the key to the starter.

Please help. Thanks!!

Oh, and only the one battery, none in the trunk.