The remote locking system only stays programmed for a short period, then ceases to work
Have replaced battery in remotes (old ones were at full voltage) so that eliminates them
Any ideas on where fault lies & how to remedy it?

Possible poor contacts in remote around batteries?

No, the contacts were cleaned when new batteries put in, besides problem exists when using either remote

Pitchfork wrote on 13. Jan 2007 at 10:08:

No, the contacts were cleaned when new batteries put in, besides problem exists when using either remote

Sorry, I meant the solder joints where the contacts meet the pcb...   ...worth a quick check.

Resoldered the joints (just in case) & no difference!
Still after re-programming, will operate once or twice then cease to respond
Any more ideas?
Where is the receiver circuit sited?

Pitchfork wrote on 14. Jan 2007 at 12:38:

Resoldered the joints (just in case) & no difference! Still after re-programming, will operate once or twice then cease to respond Any more ideas? Where is the receiver circuit sited?

If its the RF type, its behind the drivers kick panel

Yes it's RF
Are there any known problems with the receiver?
Is it fixable by re-programming etc?

Pitchfork wrote on 14. Jan 2007 at 16:30:

Yes it's RF Are there any known problems with the receiver? Is it fixable by re-programming etc?

Never known issues with receiver. I doubt reprogramming would help.

The remote buttons aren't getting pressed in your pockets etc - that could make it fall out of sync...

Is the car battery on its last legs?
Cranking a diesel from cold with glow plugs etc on might pull the terminal voltage down enough to cause loss or corruption of the stored code.
Check all the cables on the battery terminals are tight and check the earth under the battery tray.

Battery is fine, turns over well on starting even when v. cold. I'll check the terminals though