Technical 500 Central Locking failure

[nickinbattle]

The central locking on my Fiat 2007 1.2 Lounge hatchback has stopped working.

The fuse has blown and when I replace it (tried 3 times now) the locking works for probably 2 or 3 cycles, then the fuse blows again. When I click the lock button, the lights on the car flash (even with a blown fuse) but the central locking does not work

have checked where wires pass into doors and boot to see if any earth contact but seem to be very well protected on this model and cannot actually see the wires inside the wrapping, but no reason to suspect they are damaged

I can get access to the car with the manual key and start/drive .. but not passenger side or boot

Anybody got any ideas to help

 

[larslarsen]

I suspect a short circuit in the wiring to a door servo, since fuse is blown after you used the open or close door function.

Did you touched the booth open function also? If not, the booth wiring might be excluded. You might test it by using this function several times. Fuse might remain ok than.

Since insulation usually breaks in zones of bending, investigate the wiring between door and car body.

Are both doors locked / unlocked each time you used the related function? If it opens / closes one door only, the wiring of the other door might be concerned.

In case the car uses one individual wire for open and close function, you might find out the concerned wire by using the open OR close function several times until fuse blows.

Regards

 

[Mick F]

My first thought, is the notorious hatch wiring loom.

Regards,
Mick.

 

[nickinbattle]

Thanks for the advice ... something for the weekend

 

[nickinbattle]

Exactly as predicted... insulation on 11 of the 12 wires linking the body and the hatch had broken down behind the rubber gaiter. To trick just to join and or tape as all insulation hard/cracked so got an auto electrician to extend the loom. Bit of a pain to do as needed to remove cards and trim to disconnect enough to be able to pull through enough to be able to trim back to clean wire then crimp in new wires and then tuck everything back into the panels. Took nearly 4 hours of fiddling and final cost about £130.00, all works perfectly and much cheaper than letting a Fiat garage at it
Thanks for the advice and hope this helps someone else next time