300tdi Central Locking Wont Lock

Hi,
New here, so Im hoping someone out there can help!
Iv just bought a 1995 300tdi, and have a couple of issues.
Firstly, there is no central locking at all. I dont need the fob, but it all locking on the key would be very useful.
Iv had a poke about behind the drivers door panel, tried powering the actuator directly, but nothings happening. The plastic cam looks like its triggering the switch though.
Im not sure what else to check - any thoughts gents?
Iv also got an intermittent fault on the alternator - sometimes it reads 0v, other times its up to nearly 16v - I assume its on its way out, or could it be a fault on the exciter wire?
The other issue Im dealing with... leaky twin sunroofs. Two tubes of Mastik please!
Thanks in advance!
NE

If you don't need the fob u must then have an early 300 series fitted with a single button central locking/alarm system, anyway check that you have a 12v power supply to the ECU first, with the alternator if u find it's faulty then I'd replace it, the sunroof leaking, well that's a common issue therefore loads of info on how to do a permanent fix on them in the Forums.

If the alternator is giving 16v replace it as you will fry something

I may have explained that wrong - Im not sure if I need a fob or not! Rather that I personally wouldnt need to use the fob - I prefer keys.
The disco didnt come with a fob, just said key... but I found a fob stuck down inside the gearstick boot - new battery and it lights up, but doesnt lock anything, and Im only assuming its for this truck.
Anyway, I'll go find the ECU and check that as suggested and report back.
I assume if the ECU is getting power, but power isnt getting to the door, then its the ECU at fault?
Incidentally, this is the 2nd alternator in as many days - could be a coincidence and maybe the 'spare' was already faulty. -5 today. Perfect for playing with wiring outdoors...

Hang on - it is a single button fob though!

Okay, you need 12v permanent supply at the lock actuator (master), u may have a micro switch, within the drivers door to lock/unlock all the other doors (slaves) simultaneously, plus the ECU will also supply 12v short burst to the master actuator when locking/ unlocking if you are using a fob remotely.

The central locking is a very simple system.

Perfect! Thanks.
One last Q though - when just using the key then, does this mean that if there is power to the drivers actuator, and that the switch is fine, that the ECU is redundant? Is the ECU purely to recieve the blipper signal and act accordingly?

Yes but if u have the microswitch that will instruct as it were the ECU to send a 12v pulse to the actuator also the ECU looks after your immobilising, your model is in between the 200 system and the 1996MY system so a bit of a mismatch in the first 6 month of 1995.

So bottom line is, permant live or switched live at the actuator, and which forgot ....you should find a micro switch also, this tells the ECU to immobilise or not.

Thanks pal - now found the issue. The drivers door actuator is non-responsive to direct power, so I'll order a new one. Slave actuators all test fine.
Suspect ecu is also duff, but as I dont care about the blipper I can live without that.
Thanks again!