Hi,

I have  20 year old v low mileage polo which we have had since new. I have a problem with the central locking system. The drivers door lock will not open but will close the locks, linked I think there is an electrical drain which if the car is left for a while the battery goes flat. Battery replaced (twice!) but I’ve started isolating the battery when not in use. Tried several garages who haven’t a clue what the problem is or indeed whether the locking is linked to the battery drain.

Anyone experienced this or got any ideas?

 

just joined forum and not sure if I’m using it properly! Sorry if not.

 

Harry

First Welcome to the forum.

 

The door lock not opening, is that from the remote or via the drivers door key lock ? if it's from the door key it could be one of two things: the micro switch in the door lock or broken wires in the flexy rubber tube between the door and body.

 

The battery drain could be something as simple as a boot interior light or glovebox light staying on, an aftermarket radio not fully switching off or a problem with the diode rectifier pack in the alternator   

Hi,

 

Thanks for that. It’s a key operating locking system.

I have tried taking out the fuses for the lights etc but it made no difference to the drain, can’t find anything with a current meter. Alternator is fine and it drives perfectly and I have no after market things on the car. It is used rarely and I love it, will check the wiring again as you suggest.

thanks

Harry

The alternator might well be working but it can still have a problem with the diode rectifier pack https://www.clubpolo.co.uk/topic/335902-testing-your-alternator/ 

" Test the diodes, Ignition OFF, disconnect the battery NEG terminal & output lead/plug from alternator, set the multimeter to DC amps and connect it between the output terminal of the alternator and the wire/plug removed before, reconnect the battery NEG terminal if the meter reads more than 3mA the rectifier diodes are "leaking" causing a drain on the battery and over time with no use the battery will go flat! "

 

 

Hi,

Thanks again. I will try what you suggest. I have just moved house so I will need to find the relevant box with my tools first!

Best wishes

 

Harry