alternator tests fine, battery, ground strap, starter motor, and fuse box are new
baffles me to no end

My alternator tested fine too, still could not produce the amperage that the car needed. Unfortunatlely, I don't have enough experience with these cars to narrow it down, but there are lots of folks in this group that were so helpful.

Just think of the problem logically. The battery is draining while the car is NOT started? Your leaking amps somewhere.
Battery could be on the fritz. Try another one if possible to eliminate it. What are the things in the car that can draw power without the car running? Check connections to radio. In fact remove the radio for a day or so. Check your taillights. Mine were full of water and shorting out the bulbs, but never blowing fuses.
Check the main ground on the engine block. This was my only "bad" one. It is the second thick black wire that comes directly off the battery. Remove it and file the washer, 2 "o" connectors, and engine block where the screw goes in.

If you know someone with a professional amp meter, shut the car off, remove the key, and measure every fuse to see which one is drawing amps.

I hope you find it, these electrical problems suck. Let us know if you have any luck.

I had poor starting problems with my car when the bulkhead earths were playing up (poor idling, poor charging, poor starting).

Do you find that the firewall earth mount gets very hot? Mine got so hot that the rubberized cover heated up and peeled off.

Despite a good earth from battery to chassis the earth from the firewall to the brown leads were poor. I cleaned this up - so the brass around the M8 mounting thread was polished and this made no difference. I'm thinking the thread may be a nut that's brazed in and it might crack over the years - there's no other reason why it wouldn't conduct properly.

I used the mount to anchor an earth braid to an alernative mounting on bare steel. See the pic. Cleared up all my probs. Sounding like SoCal now with my earth obsession. :)http://forums.pelicanparts.com/uploa...1068589123.jpg

hmmm do euro cars have different grounds? i dont have one right there.
this weekend i am going to replace the connectors to the possitive battery cable with gold plated ones and see if i can replace the wire from the alternator. i will post if i ever figure it out!

My battery grounds onto a bracket near the wiper motor mount - or at least it did until I put a cut off switch into the line (see pic) . Note the battery is on the opposite side to US cars.

The thick grounds (brown) coming from behind the engine mount directly onto the firewall. The earths you see in the preceding picture are the work around earth and a supplement directly off the engine. They're not standard but have stopped all the problems I'd previously suffered.http://forums.pelicanparts.com/uploa...1068600647.jpg

You are not going to believe this (or maybe you will). The alternator belt was not tight enough. That is it. No electrical grounding issues.. I have been chasing this for a while. The belt was not loose by any means, but just not tight enough.

So I guess to anyone out there who is having a charging issue, make SURE you check the belt and how tight it is.