I have an auto 1995 V6 VS Commodore Executive which i have had for over 2 years without one fault up until a couple of days ago it just wouldn't start and made a clicking noise which i figured it to be the statermotor, so i replaced it got the car going and then the next time i went to start it, the same problem occurred. I then played around with my Battery terminals and found that they were drawing little to any power from the battery and moving them around and finally getting it enough power to start it would so i thought it must be the battery terminals until i left the car in park while idling to try charge my battery, and the central locking was going on and off and my rev metre kept going from low to high without reving. Now i think it has some major wiring issues maybe from the starter to the battery? i have no idea where to start and was hoping someone else might of had the same problems in the past and fixed it? Any help would be truly appreciated.
Check the main terminal at the back of the alternator - the one under the nut - it feeds direct to the battery and has a habit of overheating where it connects to the alternator which then crystallises the copper wire. You will need to remove the plastic cover from the top of the engine toallow access. Next the copper breaks as it becomes brittle. This will cause surges in voltage which all cars with ECU's do not like. If the connection looks burnt or is stiff then I'd replace that wire. Apart from that I'd replace the battery if over 2 years old and make sure all terminals are tight and squeaky clean.