Location of Central Locking Unit?

[wgage01]

I have a 1997 318ti (left hand drive). My central locking system has failed. I purchased a central locking unit off EBay and I want to swap out my non-functioning unit. Where is this unit located on my vehicle?

[VMZ]

The central locking box is located behind the glove box. You'll have to remove the glove box to access it.

[MadMax]

Hello there, I have lots of problems with central locking on my 318 convertible (yr 95).
It all started with a flat battery one morning I could not explain. After jump starting it was obvious that something was wrong with the central locking closing herratically and windows only working at times. I tried disconnecting the battery in order to reset the system but it did not change a thing.
Removed then fuses 7, 35, 43 and disabled central locking + windows for a couple of weeks.
During this period the battery gained strength and was back to normal. After 15 day and reconnecting the fuses the whole system was ok for a day or two then started to play up again, the battery is suffering and now the radio system for the central locking isn't opening or shutting at all.
I am not sure where to start to find the fault. I guess I could just change the central locking unit but I would rather have a more precise idea of what I am doing before just trying to change components................can anybody help with this one ??

I would be very grateful for some ideas on how to diagnose the fault.

[jitsjaf2009]

I cannot say for sure, but my guess would be your battery has a problem and needs to be replaced or the alternator/voltage regulator is weal in output. This would could explain the several days okay and the return of the problem. Low voltage adversely affects our systems in a myriad of strange ways. Loose or dirty grounds can cause it. Chaffed wiring or wiring "melted" to a hot manifold causing a high resistance short is possible. If you have a multimeter, shut off everything you can, leave the ignition off and remove the key. Remove the battery terminals and read between them for resistance. I don't know what it should read, but with only perhaps the clock, temp sensors, etc still drawing, it should be pretty high. Maybe 20,000 ohms or more...anyone have a better read on this?

[MadMax]

I am still monitoring the car and last week it was fine opening and shuting....no herratic behaviour whatsoever. Then 3 days of no use .....the starting motor wil not go and the problem comes back.

I agree, it is either the battery nedding replacement, the electricity generation system not capable of recharging properly or .....a leak. I would rule out the alternator as the car starts behaving fine once it has had the chance to run for a while in order to load the battery.
At this point I know for sure that:

1) if the car is stationary for a long time (2 or 3 days) the battery goes down and you cannot restart it; at the same time, when you open the door, the central lock will not work.

2)the central lock works fine as long as the battery has enough power stored in it

Conclusions: either the battery is dead and cannot retain charge or there is a leak. The central lock herratic behaviour could just be a sign of this energy problem.

Today I decided to buy a new battery to see if that is the problem. Will keep u posted !!