Had this problem a couple of years ago fixed by changing one of the hoses inside the motor but has now returned unlocks all doors but motor keeps running, locking is fine.have run it with the vac line disconnected and blocked the tube on the motor works perfectly so I assume I have a leak somewhere any common point or just a matter of checking all the hoses?
Been right thru my system and all is good now but I did have your issue before repairing SO many other problems ,someone had disconnected 2 hoses for starters the the wiring was chopped up during old alarm install . I made some blanking caps with scraps of silicone hose I had left over and tested each actuator till I isolated the issue,still a right PITA because of all the trim you have to remove . Once all the wiring was fixed I traced source of my last problem to a faulty detent on rear hatch lock ,the actuator couldn't overcome this so I removed it and latching of the lock sorted. My pump overuns for a short time after it has been used so in your case you must have a vacuum/pressure leak,good luck ,cheers.
Cheers watercooled will start checking everything pump is disconnected for now was thinking of using a syringe full of smoke to push through the system might see where the leak is but my money would be on the drivers passenger door very slow to unlock. Did notice the connector has lots of pins does this look for a signal from each lock to say it's open/closed apologies I know nothing about central locking systems.
Is it a mk2 or mk3? Mk2 does not have lots of pins, driver door has no air actuator, it is only a switch with 2 or 3 pins. If it has a remote than it should have some electric or air actuator.
Attached is a wiring diagram from Autodata. Yes, the locks send a signal tot the pump for status, locked or unlocked.
From memory the drivers door is the master but I never figured out how the pump runs in vacuum mode to unlock then switches to pressure to lock.obviously the pump must reverse direction to do that but how ? ,can only presume a polarity change but where in the system ?. Cheers.
The pump motor does indeed run in either direction; as I recall from helping someone on Gsf forum (ages ago, obviously), the circuit board controlling the pump and monitoring the return lines from the door latches has a pair of transistors granting access to the motor, as it were. Depending on which direction is required, one of the transistors 'gives way' to allow the motor to run in that direction. Then it's down to the returns and a reed switch in the pump's air chamber to show if the system has responded. I can never remember which way around the latch returns work; whether it's 12v for locked and ground for unlocked, or vice versa. Luckily, the diagram in the Porter brand manual mentions which it is. Update - it IS vice-versa; the returns show 12v for unlocked.
Thanks guys I will check over everything at the weekend. Can someone confirm its down to a leak or could it be one of switch's isn't sending an unlock signal back to the pump
Surprised the Mk3 still had pneumatic central locking!. On the MK2 there is one live supply to drivers door and that connects to one wire on unlock or one wire on lock (the switch in the drivers door controls the pump).
