During normal driving today my '94 LS400 abruptly developed a drastic electrical fault. All electrical systems gave the impression of a very nearly flat battery, the engine did remain running and the following things happened:
The display went from normal to dim.
Most of the warning lights came on (battery, oil, engine warning etc)
Outside temp display reading went haywire.
Wipers very slow.
Lack of power.
External lights dim.
Obviously this points to a flat battery as you would of course say, but the fault started immediately and while driving. The car has always started normally, is in regular use and has had no prior battery problems. I was able to continue driving to a safer place to stop, when I did and put it in Park the idle speed was hunting up and down around the 1500 rpm range. Checked belts and all visually O.K, I limped home (anxiously before rush hour and darkness) with signs of the battery growing flatter all the time. I have never encountered a battery collapse happening while in use so I'm wavering between that or an alternator failure and the fault becoming apparent when the system voltage dropped below a critical point. Has anyone experienced a similar fault?