Central locking doesn't work on one door - Renault Scenic 02

[dodgyviper]

Looking for a bit of diy advice.

The rear offside door doesn't react to the central locking blipper. I can hear the right noise from inside the door but nothing happens.

The child lock is off so the door can be opened from inside.

When I drive faster than 6mph, the auto lock clicks in and all doors lock successfully. That door can now only be opened from the inside.

Once it has been unlocked from the inside, I can open the door from the outside as well, so I'm happy the handle mechanism is ok.

In addition, the fuel cap lock does work, but it makes a long rattling sound when I try to lock the car with the blipper

Could this be a Relay somewhere or is it likely to be something within the door itself.

Cheers in advance

Dodgyviper

[Dave Brand]

Just a wild guess, really, but the fact that it locks OK when the auto lock operates suggests that it may be voltage-related. When you lock the car with the engine off you're relying on the battery, when it auto locks the engine is running so you've got the higher voltage from the alternator. Could be bad connections or a battery that's past its best.

[dodgyviper]

Thanks Dave, I'll see if the Central Locking works with the engine running.

It's an old car so a new battery isn't a shock to the system.