Technical Central Locking Busted!

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Technical Central Locking Busted!


New member
Oct 11, 2007

This problem has been on my car for about 1 month now and it's really annoying so thought I'd ask for help from the experts! (y)

I've got a toad alarm on my seicento and I used it for the remote central locking ability (plus alarm etc!) but it's now broken!

What happens is if I set the alarm, the drivers door locks then 1 second later the drivers door pops back up again and then after a couple of attempts the fuse for the locking blows. Nothing happens on the passenger side door so I'm assuming the fault is around there.

Today I got the door panel off and took a look inside and the wire that runs to the locking motor or solenoid has black electrical tape around it like someone has messed with it before or done something to it (unless black tape around this wire is normal? the Window motor one seems untouched).

Although this might not be *normal* the locking did work perfectly before the toad was installed and after for about 5 months.

Anyway, after dis-connecting the locking power block (took me ages to figure it out!) to the passenger door and fitting a new fuse the locking works and the fuse doesn't blow anymore. Although only the drivers door remote locks which is better than nothing.

My main questions are what could be causing this? I'm guessing it's something to do with the wiring / door motor or something because disconnecting it has stopped the fuse blowing and now allows me to remote lock the drivers door without it popping back up again.

Another question would be where is the motor / solenoid for the door locking? I can see down into where the connector unplugs for the power but I can't see anything that looks like a motor as it's very well hidden! How do I find it and where do I look?

I'm guessing I'm going to have to un-screw the 4 bolts where the actual catch is and then something comes loose and I pull it out towards the door pannel hole?

It's a very tight squeeze and really tricky! Unless I'm doing something wrong which is probably the case! :bang:

Any help is appreciated! :idea:
In the cinqs its normal that if you activate the C/L and a door is ajar or wont lock for whatever reason, the doors unlock. so by the sounds of it, the fault is in the passenger door as you said.

The C/L solenoid is most probably built onto the door lock/catch mechanism itself.

My assumption would be that the passenger door central locking solenoid is jammed or faulty, shorting the C/L system and blowing the fuse. What i would do is get a new lock mechanism from a scrap car and replace it.
My assumption would be that the passenger door central locking solenoid is jammed or faulty, shorting the C/L system and blowing the fuse. What i would do is get a new lock mechanism from a scrap car and replace it.

Yeah that's one of my next steps but ringing round my locals and there's no seicento sportings anywhere!

There's one being broken on ebay and the guy says he has the part but I don't want to buy one yet incase it could be something else at fault.

I would have a go at taking bits out but it's so fiddly and looks awkward I'm worried if I take something out it aint gonna go back in again lol. I can live with the passenger door being broke for now as it works fine with the key etc but I do want to fix it eventually.

Until I know 100% which bit is the bit I need to take out I'll be proceeding with caution!

I would go to the scrappers and take one out then I'll know exactly how to put one back in again but there's no sportings around me and only the sportings afaik have the central locking.

Cheers for the help so far. (y)
not sure if its same for the seis, but on the cinqs, the locking motor uses the grey/red and yellow/black wires. Someone else may be able to confirm if its the same for the seis. iirc, the motor and lock sensor wires are on seperate connectors anyway, so you want the 2 wire connector rather than the 3wire one.

So with this in mind, i would disconnect the door wiring (should be some connector somewhere to do that) and pass 12v across these two wires for a breif moment. If nothing happens, try the other way round. If still nothing happens, the motor is most probably faulty.
Whatever you do, dont do this test with the door wiring still connected to the car, as the two wires are shorted together when the motor isn't in use.

If you manage to get it to lock, the motor is fine and it could be the sensors. These are just switches to determine whether to door is locked or unlocked. So on the 3 wire connector, you have common (ground), locked and unlocked. Using a multimeter, check for a connection between ground (usually a black wire) and one of the wires when the door is locked. Then check for a connection between ground and the other wire when its unlocked. You should have one wire making contact with ground when its locked, and the othr when its unlocked. If this is not the case, the sensors are faulty.

If it passes both these tests, you need to start looking to the c/l system itself. if it fails either of these, you need a new lock mechanism.
btw, Dewsbury Road Autos (60 Dewsbury Road, Ossett) is a great place for fiat parts, probly a 40min drive or so from Doncaster, but there great people and have a fair bit of stock which you can scavenge from yourself if you wish (they dont 'stack' cars either so there easy enough to get at). I went on tuesday and they had a few seis in. didnt notice if any where sportings or not (i was after punto parts so didnt really look at them) but chances are one of them will be.