hi,

i've been having alternator issues for a little over a year now (1985 245Ti). first problem was that the mounting bushings were shot causing the belt to be very loose and the pulley wouldn't line up right with the belt. i replaced those with polys but the voltage still dropped from normal (~13v) to about 11v whenever i turned on the headlights. sometimes the voltage would return to "normal" but many times it would remain very low (though not in the red on my voltage gauge) and everything very dim.

this problem became very evident when i moved up to breckenridge, colorado where it gets very cold at night and i figured maybe the belt was slipping but that wasn't the case. so, i pulled out the alternator and checked the bushings figuring those might be bad but they were more than adequate in length. then i thought maybe the bearings might be shot due to the misaligned pulley. spinning the pulley by hand i noticed a slight ticking noise and not knowing the age of the alternator decided to replace it with a rebuilt bosch unit.

after installing the new alternator (including a new regulator) the same problem exists... what else could be the cause of this pretty major voltage drop when i turn on my headlights? i wouldn't mind so much but its getting hard to read my instrument gauges at night because they are so dim. any advice is more than welcome.

thanks,

erik

1985 245Ti, 188k