Audi 200 voltage

[Geraint Lloyd]

Guys n Gals,

I’m still having stress with starting the 200 10v TQA.

Having played extensively with the injection system and replaced or repaired
the following items that were either dead or marginal:
The igloo (from ECS Tuning), sticky carbon canister solenoid, CSV wiring,
Michelin man hose, fuel filter, slightly lose rocker cover, wastegate hose
(mind you it was pretty bloody fast before i fixed that), fuel pump check
valve, cleaned the ISV, injector leak test, ran all fuel pressure tests a
couple of times, injector cooling fan switch (vapour lock in CPR
lines!????!), plugs, cleaned cap, tested ballast in rotor, checked codes,
ran all output tests, vac lines.......

I’m sure that i missed something there though. In fact i haven’t pressurised
the inlet system for a while......

So it runs pretty well now although there may well be some fuel quality
issues going on. I noticed that the golf (also K-Jet (pure)) is no longer
firing within the first second of cranking for the first time in years.

I think that i have a combination of problems though. I think that i can
eliminate the injection as the source of the hard starting and have now
directed my attention to the electrical and charging system. 
This is because the battery keeps going dead. And when the battery is
totally toast then the car starts really well on the emergency jumper
battery, even though there is no way for it to have built up nonexistent
fuel pressure etc.

I don't appear to have an out of spec drain, but the battery has been
flattened a couple of times by junior leaving the rear interior lights on
overnight.

With a freshly charged battery and the AC off, I have 13.6v at the
alternator post.
13.4 at the jump start post
and 13.3 at the battery.

With the AC on, this drops to 12.6 at the battery and the AC head unit says
11.6v, but then it's a GM unit so it's hard to think that the figures that
it generates are 100% accurate ;). 
So i'm thinking that either the AC or the radiator fan is sucking the life
out of the battery, making it progressively harder to start. It's been warm
and humid in Montréal recently and the car spends most of its time in city
traffic, so low engine speed and the fan running at force 12. 

I have 'done' the splice and replaced all of the +ve wires at the front with
some 10AWG and soldered connections although looking at the voltages, i
think that i need to clean the starter post. The ground strap was cleaned
yesterday and had a resistance of <0.01ohms, but is pretty blue so i might
try and find a cheapo one to replace it with just for a laugh.

What voltage or voltage drop should i see with the AC and the cooling fan
on?
Do i have a problem, or is it just that the car needs more highway miles and
less city?

Any help would be appreciated!

Geraint