A lot of code readers don't communicate on some vehicles. Many of the wires in the diagnostic connector are standardized but there are some that are reserved for each manufacturer to use as they wish.
The multitude of symptoms still suggests an electrical problem that is in common with all of them. The charging voltage is on the low end of acceptable but shouldn't cause a problem. You might look at the battery cable connections where the smaller positive wire bolts to the under-hood fuse box and the negative one bolts to the body. Look for loose nuts holding a large fuse in the under-hood fuse box.
Burned contacts in the ignition switch and overheated terminals in its connector can result in low voltage to the circuits they feed. You can often aggravate it and cause problems to occur by turning on additional loads on those same circuits. As an example, cassette player reversing problems can occur when you run the power windows down or turn on the heater fan on a higher speeds.
Loose rivets connecting the brass strips inside a fuse box have been known to cause intermittent problems. One way to find this kind of problem is to monitor the voltage feeding it. Use small jumper wires to connect a digital voltmeter to the radio's switched 12 volts wire, then see what happens to that voltage when the problem occurs. You can also tap into one of the switched wires at the ignition switch or one of the fuses. Once you find a point where the voltage drops, follow that back to the previous point and check there. Keep doing that until you find the bad connection.
The same thing can happen on ground wires except you'll be monitoring for a voltage that goes up higher than 0 volts. Often you will find ground wires from multiple circuits that are bolted to the body with a common screw, and they will all be affected at the same time.
Sunday, November 4th, 2012 AT 4:54 AM