Our 91 740T wagon in the last two+ years has stopped dead on the road six times. The precursor symptoms are always the same: First the orange overdrive arrow will start to flicker, and after several days/weeks the arrow lights up without flicker and turns off only when the overdrive button is manually pushed. Days/weeks later, the radio will stop playing, go dim (no voltage) and after a second or two, the radio comes back on. No warning lights light up on the dash. This is quickly followed by a dead battery and/or alternator.

The precursors are intermittent, for no obvious reason, and are then followed by a parts failure. So far three alternators, three batteries and the ignition switch have been replaced (under warranty!). Today the mechanic replaced the battery he installed in June, saying it had a bad cell. The battery before that one also had a dead cell in March and the alternator was also replaced.

He thinks there may be a reverse polarity problem somewhere which he can't find with visual inspections of cables, parts, insulation, fuses, etc. He says the problem is like a jumper cable was hooked up in reverse. Or maybe something else can blow three batteries and alternators.

No jumper cable has been used for many years. During the last two years the only parts work was to replace the ignition switch in June, reconnect speaker wires on two door speakers and replace/paint the left front body panel after a minor accident in May 2004. However the problem probably predates this work. The last tuneup was 20,000 miles ago in 2001 before driving from Colarado (high altitude) to California (sea level). The car has 141,000 miles and is in excellent condition. Most driving is short distances (less than 12 miles) in a small city.