Originally Posted by
MarkoSolo
I'd have to have a competent diagnosis before I could make use of that.
Wrong. There is no such thing as "a complete diagnosis", you have several unrelated issues. ZERACER gave you a link with the fix for EVERY item you have listed, NOTHING you have mentioned is new to us. Do not dismiss someone when they give you a resource like that link.*
Just trying to take baby steps at the moment and discover if my guesses to root cause are in the right ball park
The symptom-function troubleshooting technique IS a form of "baby steps", that is what troubleshooting is. You address one item at a time, if there is a common element between them, you go after that first, and, perhaps, you will fix them all at once. In YOUR case, you clearly have three failures with the car that are not related.
1) Rumble under low gear acceleration and an intermittent vibration at motorway speeds... I've been told this is probably something to do with a centre bearing on the prop (any ideas? Is it a big job?)
You dont' have issues with the flex joints or center bearing until you are well past 100,000 miles/160,000km with this car. Those who have dealt with it, in my observations, were all over 150,000 miles. Either can be the cause, but crappy tires can also cause similar complaints. Special skills are not required for flex joints/center bearing, this is true "mechanic" work. Parts are not too expensive, but you are looking at 2-3 hours labor.
2) General Electrical gremlins. Mainly connected to the main stalk which does everything. The 'full beam' doesn't work. The right indicator works when it wants to. The heater controls on the centre console operate randomly, i.e; 1 blows harder than 3, and 5 is off etc... Quite comical really - I'm hoping this is all just one dodgy earth somewhere and not a whole host of issues. Your experience will be helpful here
The lighting failures both sound like a bad "Multifunction switch" (which you call "the main stalk"). That part is around $200US and is not too hard to replace but it will take up to two hours. If you pay to have it done, you are looking at the part cost plus as much as two hours labor.
Fan speeds that vary can be the "blower resistor" (easy, cheap fix) or the little potentiometer on the climate control board is bad (more difficult to get to, good soldering skills are required but the part is as cheap as $2.00).
3) Active spoiler doesn't work, either at speed or by the button - The 'red light' is on and blinks when depressed
Unless the motor is bad, fuse is blown to the motor or the gearing/linkage is frozen, its your battery. Replace the car's battery and make sure the battery posts/terminals are cleaned with a wire brush.
It is possible this is due to a bad wheel speed sensor, but in such cases you will usually get a "BAS/ESP" light on the panel.
One more thing:
There are forum members who travel and fix Crossfires for no, low or little labor charges. We even have a member from the USA who is traveling to the UK this summer to do a "repair tour". You may get more help by giving your location, this is an international forum, "Bournemouth" is not a location. Change your "location" to indicate where "Bournemouth" is.
*In general, based on your post and response to ZERACER, my advice is to consider selling the car as-is for what you can get. You seem unprepared and less-than-willing to put the effort into getting this fixed, I think selling would be easier IF you can find a buyer willing to put the effort into the car. Here in the USA, such buyers are everywhere to the extent that, on Facebook, a car like yours attracts such buyers more than a car in ready-to-sell condition will attract average buyers. (It's people looking for a deal and a challenge. Many of us can do the work ourselves, making the car a good buy and your issues are all well-known, common problems; not much of a challenge.)