One item prone to fail is the ignition switch. There are detailed instructions with pictures on the Web. You have to remove the plastic trim pieces under the steering wheel. There is a signal plug that needs disconnecting and a one small Phillips head screw that hold the switch in. This screw is in an awkward location and use a small driver to get it out. No need to get a new key mechanism. The switch is only about $12 from Europarts SD. The other part that also can fail is the ignition coil (only one on the early models) that is located BELOW the battery. You can check of the plugs are getting a spark with a inductive timing light placed around the coil leads. The newer T4's have a coil mounted with each plug... I think. Good luck! W. Li 1995 T4 Camper
I am sure that my method outlined above is not original, and has been written up somewere else. What I can vouch for, is that I have performed this test on my 1993 Volvo 240 wagon with over 200K miles.. Its brakes had been pulsating for some time, and after checking the ABS electric components exhaustively; it was only after replacing all four original disc rotors, that the pulsations disappeared. The front pair of rotors had 1.5mm ridges, were replaced first, with most of the pulsations gone. However, there were still minor ones, which disappeared once the rears were replaced. Theoretically, turning the rotors on a lathe could have removed the warp, but then the discs would would be thinner, and more susceptible to thermal distortion. I recommended that this kind of work be performed in a licensed brake shop, simply because not all readers have the proper tools or training to do such critical work in a home garage. Failure to securely remount the calipers could result in severe injury.
Caution in pulling the power button cable and power-on LED cable off the motherboard. DO NOT TWIST. They are supposed to lift straight out if you believe the Apple tech manuals. Mine would not budge will gentle pull, then broke when the pull was increased a little.
PS from author
I am sure that my method outlined above is not original, and has been written up somewere else. What I can vouch for, is that I have performed this test on my 1993 Volvo 240 wagon with over 200K miles.. Its brakes had been pulsating for some time, and after checking the ABS electric components exhaustively; it was only after replacing all four original disc rotors, that the pulsations disappeared. The front pair of rotors had 1.5mm ridges, were replaced first, with most of the pulsations gone. However, there were still minor ones, which disappeared once the rears were replaced. Theoretically, turning the rotors on a lathe could have removed the warp, but then the discs would would be thinner, and more susceptible to thermal distortion. I recommended that this kind of work be performed in a licensed brake shop, simply because not all readers have the proper tools or training to do such critical work in a home garage. Failure to securely remount the calipers could result in severe injury.
Very nice presentation, with excellent photos.
Caution in pulling the power button cable and power-on LED cable off the motherboard. DO NOT TWIST. They are supposed to lift straight out if you believe the Apple tech manuals. Mine would not budge will gentle pull, then broke when the pull was increased a little.