On a similar topic to :
http://www.gtmdrivers.com/forum/is-the-rossa-loom-plug-play-or-are-mods-needed-t1058.html
I've just fitted a new replacement Indicator/Horn/Dip Switch Wiring column switch to my Mk1 Rossa, and plugged in the matching plug and low and behold I get the Horn on left turn, no dip, right turn on headlamp flash etc.

I assume its a case of Mini Switch to Metro wiring?

Further investigation shows joins in the old switch wiring where I assume this problem was rectified by the builder/previous owner.

Is this the norm (to cut and shut) or can you adjust the connections at the switch end?

I also notice that the Self-cancelling collar needs to be trimmed off to allow the steering wheel boss to fit. Again is this standard practice.

The Allegro switch is the one that is a straight plug in with all wires matching and it has heavier contacts and cable as no relays are used - but you try getting your mitts on an Allegro switch nowadays!. My query was because I wanted to fit the later and better looking Metro switch but I've canned that idea for the moment because it looks as if it's a big job to alter the wiring and I'll likely make a dogs dinner of it anyway Your problem sounds like the one I had when I fitted a Metro ignition switch instead of the Allegro one and the wires and fittings didn't match the loom so I had to chop them off and join the wires off the old switch but it did work, though.

I was just about to start cutting and splicing cables but was unhappy that this would mean mismatched cable as some are thicker than others. So as the pins are "loose" in the plug I tried and magaged to ease one out a pin. So in the end I was able to remove all the pins and using the old switch as a template "re-wire" the plug so that all the functions worked with no cable cutting.

I was also pleased I had done it this way as in the process one wire just easlily separated from one of the pins.It seems they are only mechanically crimpted and this one not crimpted very well. So along the way I soldered all the wires to the pins.

I also drilled, tapped and inserted a couple of 4mm studs into the back of the steering wheel boss to engage with the self-cancellng collar.

All in all I'm hapy to tick off another job done. Now to sort out the wipers, two spindles that turn in posite directions , one central wiper and no self park. Off the car the motor works at two speeds and self parks. Just need to refit and turn into a working system.

Glad you got it working I haven't tried my wipers yet............

I've heard it said this makes a point of failure as it's less flexible - not sure whether to believe it or not

I would thinkt not, the solder is in the centre of the pin, the wire is still flexible from the pin onwards.

Refitted the motor, change the domestic "choc-box" type connections for proper auto ones, wired it up and it works! central wiper parks in front of driver OK so I think I'll remove the redundant spindle and block the hole with a Grommet.

Question: On the big gear wheel in the wiper is a hole marked 120 deg. Will that give me a bigger sweep (I assume the standard is 110 deg?)

The failures in the solder joints are at the point where the solder stops and the unsoldered cable begins. One is solid and the other can move, therefore giving a point which can work harden. I always try to avoid soldering on anything where vibrations can cause this to happen over time, like on cars. If you do need to solder a joint though, make sure that it is well supported on the cable, so the movement is down to a minimum. Otherwise you eventually get a failure and it WILL be when you least want it!!

I tend to crimp the smaller gauge low current wires and solder the larger gauge high current ones.

Solder embrittlement is always a problem and soldered wires should be supported to prevent flex but in the case of a multi-plug just clipping all the wires together with a cable tie as they exit the plug is probably sufficient.

My feeling is that a good crimp takes less skill than a good soldered joint and a bad soldered joint can be every bit as bad as a bad crimp.
I found out a while back that aircraft harnesses use exclusively crimp connections so that must mean something.

I stand corrected, who says you can't teach an old dog new tricks