Central locking not working

[LeedsMike]

Hi there,

I'm new to the forum having just bought a S2 1995 (#388). As you do, I'm going around the car trying to get myself a list of jobs together and noticed that the central locking was not working.

The car looks like it had the factory fit alarm/immobiliser originally, but no fob keys were supplied (just some old school ones).

Issue is the same when trying the key on both sides and trying to lock from the inside.

The fuse diagram doesn't mention locking so thought I would ask on the forum for some early pointers.

Thanks in advance!

[Saltire]

On the S2, the central locking is driven directly from the OEM alarm, so unless that’s working correctly (or has been replaced by a CL-compliant alternative), you won’t have central locking.

Sorry

[LeedsMike]

Thanks, that’s helpful.

[Saltire]

To amplify my reply from last night slightly (I’d just got back from a tiring day at the NEC Classic Car show): unlike the earlier SE (and NA) cars, the S2 has no specific central locking module under the dash. Having said that, much of the wiring and triggering of the locking mechanisms is as described in section MJ of the workshop manuals. These are available under the “Manuals” link, available at the top of this page when you’re logged in (although looking at your forum profile, you MAY not have enough posts to be able to see them. If this is the case, let me know and I’ll ask a friendly mod to facilitate).

Depending on how handy you are with car electrics, you can test the central locking without the alarm by sending an ‘open’ or ‘close’ pulse down the connections to the lock motors. This would confirm whether the problem is the alarm (as I suspect) or the lock motors themselves.

Let me know if you’d like me to post the relevant circuit diagram.

Hope this helps

[Tuga2112]

To amplify my reply from last night slightly (I’d just got back from a tiring day at the NEC Classic Car show): unlike the earlier SE (and NA) cars, the S2 has no specific central locking module under the dash. Having said that, much of the wiring and triggering of the locking mechanisms is as described in section MJ of the workshop manuals. These are available under the “Manuals” link, available at the top of this page when you’re logged in (although looking at your forum profile, you MAY not have enough posts to be able to see them. If this is the case, let me know and I’ll ask a friendly mod to facilitate).

Depending on how handy you are with car electrics, you can test the central locking without the alarm by sending an ‘open’ or ‘close’ pulse down the connections to the lock motors. This would confirm whether the problem is the alarm (as I suspect) or the lock motors themselves.

Let me know if you’d like me to post the relevant circuit diagram.

Hope this helps

i think we need to write an extensive FAQ about the central locking in both SE and S2 with notes about the usuall issues found with aftermarket alarm instalation in both cars.

[dapinky]

i think we need to write an extensive FAQ about the central locking in both SE and S2 with notes about the usuall issues found with aftermarket alarm instalation in both cars.

If you, Jonathan, Pete, Simon and/or anyone else with the accumulated knowledge wish to write something up, I'm happy to host it with the 'other' stuff (and can hide it behind a password if it is 'sensitive' information).

[Saltire]

I have a fairly comprehensive write-up of the S2 alarm and locking systems,but I know relatively little about the SE/NA arrangements beyond what’s in the manual. I’d be happy to try to cobble something together / update my original, but I’d feel a lot happier if Pete and/or Simon P were to check it afterwards to make sure I haven’t said anything that’s just plain wrong

Pauline has the dreaded lurgy at the moment, so I’m in my starched cap and apron ministering to the sick, but as soon as things improve I’ll give it some attention. I can recognise a Pinky when I see one

[Tuga2112]

my experience from the SE matches the manual extremely accurately.

only things i would be adding notes about is the "tipical" aftermarket instalations have the habit of triggering the solenoids in 2 different ways, (attached to 3 different wires) which in turn sometimes can be partially diagnosed by the bheaviour of the system .

location and routing of the wires is something that the manual lacks detail on, which a few pictures (or videos) could help clarify as well.

[LeedsMike]

To amplify my reply from last night slightly (I’d just got back from a tiring day at the NEC Classic Car show): unlike the earlier SE (and NA) cars, the S2 has no specific central locking module under the dash. Having said that, much of the wiring and triggering of the locking mechanisms is as described in section MJ of the workshop manuals. These are available under the “Manuals” link, available at the top of this page when you’re logged in (although looking at your forum profile, you MAY not have enough posts to be able to see them. If this is the case, let me know and I’ll ask a friendly mod to facilitate).

Depending on how handy you are with car electrics, you can test the central locking without the alarm by sending an ‘open’ or ‘close’ pulse down the connections to the lock motors. This would confirm whether the problem is the alarm (as I suspect) or the lock motors themselves.

Let me know if you’d like me to post the relevant circuit diagram.

Hope this helps

If you could point me at the correct diagram, that would be great.

I did check the alarm fuse and it’s still in place so there is power to the circuit. All I can assume is the entire setup has been disconnected.

[Saltire]

The diagram you want is Sheet 29 of the “S2 Wiring” manual which you can find by clicking on the “Manuals” link at the top of this page.

If you’d like to PM me an email address, I’ll send you my write-up on the S2 OEM alarm system (although I am currently revising it to be included in the Manuals section).

Hope that helps!

[LeedsMike]

The diagram you want is Sheet 29 of the “S2 Wiring” manual which you can find by clicking on the “Manuals” link at the top of this page.

If you’d like to PM me an email address, I’ll send you my write-up on the S2 OEM alarm system (although I am currently revising it to be included in the Manuals section).

Hope that helps!

PM sent.

Those diagrams are great. The stereo one helped me to understand why the switched ignition live is actually always live…!

[peteoddcar]

Ah
The Elan CL system. Caused me a few sleepless nights back in 1989 I can tell you.
The SE parts are GM parts bin of the era, but not from the same platform so they aren’t really a system hence the add on micro switch on the latch assembly.
S2 I had nothing to do with but I will investigate and try to get some sort of guide to diagnose issues from looking at the diagrams.