I've been having problems with fuse number 21. (clock / interior and boot lights / central locking / diagnostics).

It blows as soon as it's replaced.

I've recently noticed that the nearside brake light is full of water. and I've heard that the central locking pump is located behind one of the rear lights?

Is it likely that this is what's causing my fuse to blow? If so, how do I rectify this? How do I replace the pump?

I dont know if this is any help, but on my polo, I had a leak in the boot and it turned out to be the water tubing for the rear washer, it had come apart just behind the rear passenger light cluster, it also happened to be over a set of connections which was causing the rear lights to play up when braking, indicating etc. Might be worth a look, just dried out the connections and sprayed a load of contact spray on it to future protect it.

Hi mate yeah this is pretty normal for polos, I suggest removing the rear light making sure the rubber seal hasn't perished if so grab another from a scrap yard, tighten it back up making sure the seal is flush. The central locking problem is down to the leaking gap around your light getting into the pump, just under where your first aid kit is should be the pump I'd say take it out by undoing the connector and air hose and make sure the connections are clean and there's no water damage if so replace it(I have one for sale if you want it) hopfully it shouldn't leak and short out the fuse. :-)

Hi, thanks for your answers

I disconnected the pump this afternoon and tried replacing the fuse. The fuse blew again . This means the central locking pump isn't the issue right? What do I do?!

Check the connections to the rear light and the earth which is just next to the pump

Check the connections to the rear light and the earth which is just next to the pump

Thanks for your reply. The light seems to be fine 'cos its on a different fuse and circuit to the one that blows. Frustratingly.