Central Locking Dead

[Sam940]

Hi guys,

New member and relatively new 940 owner here. I own two Volvo 940s, a 1995 940 S n/a manual and a 1997 940 Celebration LPT manual.

My ‘97 940 has had an issue since I bought the car I’m struggling to diagnose. The central locking is completely dead. Each door locks fine manually but it’s as if the central locking is non functional. I have swapped the central locking relay with my ‘95 940 which has fully functional central locking and did not fix the issue. fuse 2 is also working fine which I believe protects the central locking circuit.

Any ideas where to look now? I am relatively unfamiliar with the 940s but gradually learning. If anyone has any pointers for any common fixes to this issue I would be much appreciative.

[Laird Scooby]

Originally Posted by Sam940

Hi guys,

New member and relatively new 940 owner here. I own two Volvo 940s, a 1995 940 S n/a manual and a 1997 940 Celebration LPT manual.

My ‘97 940 has had an issue since I bought the car I’m struggling to diagnose. The central locking is completely dead. Each door locks fine manually but it’s as if the central locking is non functional. I have swapped the central locking relay with my ‘95 940 which has fully functional central locking and did not fix the issue. fuse 2 is also working fine which I believe protects the central locking circuit.

Any ideas where to look now? I am relatively unfamiliar with the 940s but gradually learning. If anyone has any pointers for any common fixes to this issue I would be much appreciative.

Will the central locking operate if you lock/unlock from the passenger door?

[Sam940]

Nope, it’s not operative on any door. My ‘95 940 only works on the drivers door too and I figured that was normal. Perhaps there is an issue with both!

[tofufi]

Originally Posted by Sam940

Nope, it’s not operative on any door. My ‘95 940 only works on the drivers door too and I figured that was normal. Perhaps there is an issue with both!

Same on my '90 740 (only works on driver's door), but can't speak for other vehicles

I'd imagine the switch to operate the C/L in the driver's door is faulty.

[360beast]

Originally Posted by tofufi

Same on my '90 740 (only works on driver's door), but can't speak for other vehicles

I'd imagine the switch to operate the C/L in the driver's door is faulty.

Completely agree

[Laird Scooby]

Originally Posted by Sam940

Nope, it’s not operative on any door. My ‘95 940 only works on the drivers door too and I figured that was normal. Perhaps there is an issue with both!

On the 95 i would expect it to only operate on the drivers door, later cars (according to some diagrams i've seen) sometimes have a switch in the passenger door so as the faulty one is a 97 car, it has that possibility.

As mentioned above, chances are the drivers door switch (built in to the lock motor assembly) could well be faulty or have lost its earth connection.

Just to clarify, it will neither lock from an unlocked state nor unlock from a locked state with central locking?

[Sam940]

Hi guys, thanks for the suggestions. I’ll be sure to give some a go tonight and update.

@Laird Scooby, correct, it will not lock from an unlocked state or unlock from a locked state. This is the same with any door. The only way I can describe it is as if the central locking system is completely dead. I will have a good look tonight to see if I can see any loose connections anywhere.

[Laird Scooby]

Originally Posted by Sam940

Hi guys, thanks for the suggestions. I’ll be sure to give some a go tonight and update.

@Laird Scooby, correct, it will not lock from an unlocked state or unlock from a locked state. This is the same with any door. The only way I can describe it is as if the central locking system is completely dead. I will have a good look tonight to see if I can see any loose connections anywhere.

There should be a 3-way multiplug connector from the switch that will connect into another 3-way connector, usually fairly visible once the door card is off.