Maybe a little late here but i have a fix for this after turning down my dealers generous offer of a 750gbp fix i did some extensive googling and found this.... With your ignition on open the tailgate using the catch inside then turn off ignition and disconnect the battery for a minute. Reconect the battery and turn on ignition and let the warning lights go through their cycle. With the ignition still on shut the tailgate and hey Presto should be as good as new.
Six cylinder: The air cleaner element is inside the air cleaner housing on the left side of the engine compartment. (It has a large hose connected to it). To replace it: Disconnect the hose from the air cleaner housing cover with flat-tipped screwdriver. Loosen the four bolts, and remove the air cleaner housing cover. Remove the old air cleaner element. Carefully clean the inside of the air cleaner housing with a damp rag. Place the new air cleaner element in the air cleaner housing. Reinstall the air cleaner housing cover, and tighten the four bolts. Connect the hose to the air cleaner housing cover with a flat-tipped screwdriver.
bushes in the motor are warn if it rotates slowly. or slows down then cool off period and its fine. you can replace them but its usually more easier just to change the starter motor, when replacing the motor ask when you get new one if they pay for return of old motor as some places will either give you monies off or money when you bring in old one.
Looking at wiring diagrams , using A DMM- digital multi-meter an testing the electrical circuit's is the way to find the problem . Because without testing anything said on here would just be guessing . Someone mite get lucky suggesting something to replace, this or that . You could replace a bunch of parts too , before fixing the problem. There is a relay in the electrical circuit that egages the compressor clutch on command from the PCM/ECM -engine computer . Windshield wipers problem could be a simple loose connection ,ground or voltage . Or the motor could be getting ready to go out all together .
Free wiring diagrams here http://www.bbbind.com/free_tsb.html
Enter vehicle info. year , make , model an engine size . Under system click on HVAC ,then under subsystem click on HVAC controls . Click search button then the first blue link . Shows fuse's ,relay ,A/C pressure switch , evap. temp sensor . All these have to be right or the computer will not turn on the compressor . The computer would also have to see a command from the HVAC control head . Alot has to happen before the computer will turn on the A/C . Electric Testing Techniques You Need to Know
sounds a bit like a worn ignition key barrel. if the barrel wiggles by applying pressure to the key then its probably time to replace it. most barrels last about 90K miles, or about 10 - 15 years of use as a rough guide. but obviously some cars travel that distance in 2 years or less and will still be very good as far as a key barrel goes. you may need to dismantle it and have a look. you could always tap in a 12v supply from something else to the radio temporarily and see if the speedo stays good. may be fog lamp switch?