rear hatch unlocking blowing no 1 fuse - update

[eddieedmo]

Finally stopped raining so looked at the problem.
1 disconnected the lock microswitch from the connection to the motor loom( white plug connection under lock ) and unplugged motor from loom( black barrel connector) - no blown fuse
2 reconnected microswitch and left motor unconnected - no blown fuse
3 reconnected motor as well , one turn of the key worked once then blew fuse

So it must be a problem with the motor or wiring to its black connector .?

Just for piece of mind pulled each fuse in turn to check all other circuits and only no 1 fuse showing extra power being pulled (used a test light on neg terminal of battery )

As to where the in car switch gets its power from I don't know ( still works with no 1 fuse blown ), but will find out for piece of mind by pulling each fuse in turn when I get the lock opening sorted.

Thanks again for all the pointers , will fit another motor I have spare first of all then will investigate the bad one.

Nick []

 

[bertelli_1]

Does the sunroof blow the same fuse when you operate it? I would try the replacement motor first as there is a switch inside which could have shorted I suppose. Also the feed to the microswitch goes to the motor & relay g19, try operating it with g19 removed & see if that makes a difference.
If that fails its time to get the multimeter out...

eta: just checked the wiring diagram - try the motor first, thats still the most likely fault. Then, there are 4 wires on the microswitch? The brown/white wire goes from switch to motor, check it for a short to earth.

 

[eddieedmo]

The sunroof operates fine and doesn't blow the no 1 fuse and the in car unlocking switch works fine it is just the key operated lock on the rear that blows the fuse.Where the in car switch is fused through is a mystery but obviously not no1 thank goodness.
Will put a spare motor into the connector and go from there.
Thanks for the info. is the relay in the main fuse board or hidden away somewhere else.

Nick []

 

[bertelli_1]

I think its in the main fuse board. But since I checked the diagram I don't think its the culprit.

 

[eddieedmo]

Quick update , I plugged in the spare motor and same happens , ok from in car switch but when I use the key in the rear lock it blows the no 1 fuse , so I conclude the problem must in the wiring from the microswitch to the motor socket.Is there an easy way to find the problem apart from stripping the piece of loom and physically looking ?

Nick []

 

[bertelli_1]

get your voltmeter out & check the brown/white wire for a short - if you dont have a voltmeter you could just strip back the wiring. Also, if the switch is faulty it could be switching 12v straight to earth, this could be checked with a voltmeter.

 

[eddieedmo]

several fuses later still have not solved the problem.The wiring to the microswitch has 4 wires 2 red(from main loom which go to one red at white microswitch connector ) which show 12v , white showing 0.09v and a brown /white showing 0v - with good fuse and not switched.There is continuity along the brown/white to the motor and the red wires to the motor.
The barrel connector to the motor has 4 wires -red , brown , brown/white and red./white.
Any ideas anybody.

Could someone explain the sequence of events when the switches to unlock the hatch are activated and how the in car switch is linked to the tailgate lock/switch so I can understand and also suggest a logical way to find the fault.

Thanks

Nick []