Regulator/alternator strange problem?

[Reidar]

Hi guys!

I have some problem with the charging on my -68.
Cruising down the road my alternator-guage suddently drops to negative charge. After a while it pops up to positive charge.
Up and down, up and down. It doesent seem to be any loose wiring anywhere.

I have changed the alternator last fall, but I have a feeling it might be the regulator.
According to my local part-shop the regulator I need it called w-106.

The one that was in the car when i bought it, doesent look like a original one..


Does anyone had this problem? Or know what i should try?

Regards,
Reidar

[Nacho-RT74]

I don't think regulator itself... I have had that problem and looks more like three things:

-Broken wire up to brushes or those that feeds regulator.
-Loosen terminals at brushes.
-Damaged Brushes isolators, or brushes itself. Is not rare that some time on an alt life with all spins, heating caused for friction, melts the isolator and get out of place the brushes making shorts. Also worn bearings and housing produce brushes and isolators damage.

[Nacho-RT74]

the alt  on pic looks more like a squareback alt ( not sure ), used since 70 up 76-77 with electronic ignition system. Is not the right one for a 68, but if you have electroniic regulator, then everything is good, was upgraded... if is still working with mechanical regulator, then probably one of the brushes was grounded, and will work the same than earliers round back alt.

Since 76-77 alts used same system and working design but Alts were cosmetically changed with a complete covered stator by housings and slightly changed on interior with wider stator to get more charge output and also better idler charging.