Okay for those of you that have a vehicle fitted with vacuum operated locking there is one inexpensive thing you can do yourself which MIGHT (emphasis on might) solve your problem.

My 1988 300 CE seemed to delight in making me put the key in the lock every so often to unlock/lock the car. (it seemed to do it a lot when it was raining - who says the car doesn't have a mind of it's own !)

When I had a Mongoose M40 immobiliser fitted last week the installer had some problems getting it to operate off the new "remote" Mongoose provided with the system. One minute it would work the next not !

Now for the uninformed, the locks are operated by a system of tubes from a Vacuum Pump located underneath the rear passenger seat (RH side here in Australia) and is encased inside a plastic box which when opened reveals a circuit board & a vacuum pump with two hoses attached to an "L" shaped spigot.

It appeared to be a viable system of electronics and the vacuum pump I know was quite new (according to the guy I bought the car off).

There are two short rubber lines leading from the vacuum pump.

These go to :

1. a plastic spigot pointing upwards from inside the outer casing (and thence to the various locks around the car)

2. back to the middle of the circuit board where another plastic spigot sits.

As you can see from the attached picture, the reddish colored line is quite stretched at the opening ! This was the case on both pipes at both ends.



So as a cheap attempt at a remedy I ventured to a local European Car Workshop and he gave me around 7-8 inches of new vacuum line (the black tube in the picture). Make sure the pipe is pliable as it needs to be easily bent around without kinking.

Presto - Lock Unlock Lock Unlock Lock Unlock wait awhile Lock Unlock

And better than it ever did before !!!
So for the sake of a couple bucks worth of new pipe and less than half and hour labour - FRITZ now locks and unlocks perfectly !