I also had a problem with headlights dimming, radio and a/c cutting out. I tried the recommened fix by replacing the positive battery cable. I my case this did not fix the problem. I also had a reading before & after replacement of 12.8 volts coming off the alternator and battery voltage of 12.3 volt's. So I took the car to the local parts store for a battery/alternator test. Turns out that the alternator was fine, but battery only had 1/2 of the CCA Amps. Replaced the battery but problem still remained. Next I went under the hood and cleaned evey ground terminal I could find (removed battery, and air filter box). The ones I cleaned were battery to chassis, transmission ground cable (located on right side of engine compartment from front, ends under removed assemblies), motor ground cable (located on left side from front, on top of motor mount ends on inner fender). Also cleaned PCM ground (located on right side of engine compartment, appx 5 small black wires terminated on inner fender. Also cleaned 2 more small black wire grounds (did not trace back to see what they were for. After I cleaned all terminals and sanded paint off all painted parts I reassembled using Di-electric grease. It's been 2 months now and everything is great. Also electrical system sems stronger ( even my remote key fob is working better) and getting 14.5 volt reading from alternator with all heavy electrical loads running. I do beleive that anyone with minor mechanical apptitude and 10 & 12 mm wrench andsockets can perform this repair. I would try this before replacing the positive or for that matter any negative cables.