battery light flickers at idle

[neimis]

Symptom - battery light flickers very dimly at idle (850 - 900 rpm.) As soon as the revs rise to 1000 or above, light disappears. Also, as soon as there is a load (eg. rear window defrost) the flickering disappears.

Battery is brand new, alternator is newly rebuilt, all electrical connections cleaned and tight. Battery measures 12.5 volts, alternator puts out 14.3 at all rpms, measured at the alternator and at the battery terminals. Flickering light also existed before installing the new battery and alternator.

Is this some sort of "known issue"? Has VW emulated Microsoft and declared this to be the "norm"?

Car is a '92 Passat TD, any ideas?

[Vincent Waldon]

Pretty common issue as our cars get older and is usually the result of aging grounds...battery to chassis, chassis to tranny, block to alternator contact.

If you search for "grounds" you should find lots of ideas.