Hi snova, meant to get to this earlier but I've been busy......
You are correct, cab and coupe differ with the intervention of the alarm.
Your short cct likely comes from one or both of a couple of possibilities: The wipers in the motor have become misaligned (most probable) or the diode has broken down (possible, but its rating is quite high). I doubt wires have burnt out as that is what fuses are designed to stop. You may have a wire shorting to earth, but let's look on the bright side.
I'm going to post a photo of my notes in a minute, but note I have a cab so it is slightly different; I can use fuse 28 to help troubleshoot. Anyway .....
Test for motor wipers ..... Drive the motor manually until "parked", plug the motor back in and then put the fuse back in. If it doesn't blow then it is surely the motor wipers. ("Park" is when the motor arm is pointing towards the boot/trunk cable ..... so you will need to note this direction.
Process .... You can drive the motor by undoing the motor plug-socket and applying 12v to the red wire (pin 1) going to the motor. However there is an element of risk to the chosen wire, so I recommend removing the motor from its mount and taking it to the battery.....
Put the motor casing on the battery -ve and apply 12v to the motor red wire (pin1). The motor should rotate and then stop. It is now at "park".
Now apply 12v to RedWhite (pin2). If the motor rotates then your diode is good. If the motor starts to glow and you can smell burning flesh, then remove power from pin2 and put the motor down carefully so as not to dent, or get newly seared flesh, on your front wing .... only half joking, maybe just slow-tap 12v against pin2, if the motor jerks then it is trying to move so all should be good. If it does noting then maybe skip that and move on to the next section
Assuming you are not now at A&E ..... time to service the wipers ...
The plastic cover is removed by sliding a flat screwdriver under each of the 3 tags in turn and easing up the white cover (nothing should jump out as the wipers are just bent metal, not coiled springs; as always, go easy on old plastic)
Look on the contact plate to see the path the wipers are taking (after 25 years it will be slightly grooved, but not too bad, see dotted lines in my notes/drawing of wiper section) .....
The outside wiper should run on metal until it reaches the plastic "park" section
The middle wiper runs continuously on metal
The inner runs on plastic until it reaches a small metal pad ... also in the park section..... this inner wiper is the likely suspect. If it has moved out onto the metal then it will short red and/or red/wt to ground.
Clean up the contact section, gently bend the metal wipers sideways if necessary, put the white cap back on (start with the clip under the wires as that bit is most fiddly, also when you have that one in place you can still peer into the wipers to see how they seem to be lining up).
To test ..... plug motor in, run a wire from the motor chassis to 968 chassis. Ensure neither motor arm or electrical wires will touch anything. Insert fuse ...
If it immediately rotates it should also park.
If it does nothing it is either already on park so you need to press a switch/ turn key, or the motor is not properly earthed, or ..... the fuse has blown again :whine: :whine:
I hope this helps, good luck!
