Nellis50rennlist

2003 911 turbo has short in c3 and blows fuse immediately when replaced. The windows do drop when opening doors. Everything else works the way it should. I've disconnected the doors at the hinge connector, the engine compartment at the main connector, the window switches, the overhead console connectors, the light in the boot, the door lock switch, the light in the glove compartment and have looked for any rodent damage and can't find the fault. I'm at my wits end! Any ideas of what else to look for would be greatly appreciated.

jpflip

I guess , with all the connectors and wires disconnected you still blow the fuse....C3 is also for the alarm system. Did you look at the control unit under the driver seat?

jpflip

When you look at the alarm system on the wiring diagram, the power from the C3 fuse goes to the "central locking button" (switch in cabin, you should look at this one), to the sun sensor, the interior sensor, tilt sensor...

jpflip

After looking at the wiring diagram, everything seems to point towards the CU Alarm system which is the box under the driver seat.....

s65e90

Take the door panel(s) off and check the wiring going from the main harness into the door switches. I have seen them get crimped, short and do exactly what you're saying. blowing fuses and causing issues.

jpflip

There are several fuses related to the power window. Do you remember which one was at fault in your case ? It can be D1, B6 but C3 seems to be out of the picture... But I think Nellis50rennlist eliminate this possibility by disconnecting the connector going to the door....

Macster

Just some general help. As others have offered check the security module under I think the driver's seat. What you are looking for is signs of moisture. The body water drains often get blocked with plant litter and rain or wash water collects in the basins and overflows and overflows into the cabin. The security module is located at the lowest point in the cabin and of course this is where the water goes.

If the security module is dry and the water drains are free of trash build up check the door bottoms for signs of moisture. What can happpen -- it happened with my 2002 Boxster -- is the door membranes fail -- due to age -- and let water from the wet side of the door to the dry side. This water can result in electrical gremlins with the door and window electronics/electrics initially but if ignored can cause electrical gremlins to appear elsewhere.

The door card will have to be removed and a check made for any water in the door. If found the membrane should be replaced. In the case of my Boxster the tech tried regluing the old membrane in the passenger door and he did a good job but the membrane tore and moisture was at the carpet again after a wash or rain. The old membrane was just too old. I note you have a 2003 Turbo so it is just a year younger than my 2002 Boxster. (I too have a 2003 Turbo and I check the door bottoms, the carpets, after every wash or when the car has been out in the rain. At the first sign of wetness I'll book the car in to have both door membranes replaced.)

Carlo_Carrera

The short might also be in the wire harness bellows in the door jam. Easy to check.

Nellis50rennlist

Thanks how do you get to that?’

Nellis50rennlist

i did find the fault was either in or beyond the alarm box. It clears int the box but when I connect the second set which I assume goes to doors, Etc. it blows.

cwsamuels

I have a 2002 Boxster that whenever I install a 15 amp fuse in C3 (as referenced above) the door locks begin clicking continuously.......
Currently I have to install the fuse to lower the windows and remove the fuse as soon as the windows are down.
The central locking button on the dash does not light up or activate the locks. Also the locks will continue to pulse even after the vehicle is off and the key is removed if I leave a fuse in C3.

Ideas as to the problem?????

THANKS...

2jzhx60

So how did you fix this again? I cant make it by what you wrote. I am having the same issue with the C3. It works for maybe 5-15min but then the fuse blows. Im still in early stages figuring this out.

Dock

His last post was over five years ago. Hopefully he'll be back and can answer your question.