[Mk2] [Turbo] BATTERY CHARGING PROBS

[vinnyl]

car (1993 turbo) been parked up for over a year but been let run on idle every month
two weeks ago while cleaning it and getting it ready to go back on the road left it idle for about a hour all was good
then yesterday went out to bring it for mot batt was dead not fully but when i went to start it ignition would just click so i put booster pack on it still the same so then put jump leads on it from another car and started but battery light and malfunction indicator light stayed on drove about 100 yards car cuts out so put a new battery in it started fine but lights remain on drive it 20 miles to mot but amp meter in car showing battery volts drop put a amp meter on it at idle and it show 12v rev the car still shows 12v put on radio lights shows 10.4v
on way home batt voltage drops and car cuts out put in another new battery and get car home
i presume its the alternator that s gone but before i go replacing it would it be anything else thats causing the problem
and if it is the alternator any ideas on what i should be paying on parts and labour to get it replaced
all help appreciated

[paul port]

The alternator main output cable is fused, so is the battery voltage sense wire, so is the alternator power wire!

you need to go round and check the fuses:
Main Output front bonnet : ALT 120A
Remote Sensing front bonnet : Alt Sensing 7.5A
Power Wire Engine Bay : ECU-IG 7.5A

[vinnyl]

checked all fuses all ok so def not a fuse

also i started it to see was there any error codes but its not reporting any and now another light has come on in the dash the one that means there is a prob with the cooling fan