standard125r, when the car died on your daughter it was likely due to worn voltage regulator brushes resulting in the alternator not fully recharging the battery. A new voltage regulator costs around $15 and is an easy DIY repair. 2 screws secure the voltage regulator to the back of the alternator. Your old voltage regulator is probably long gone, but I would attempt to retrieve it and check the condition of the voltage regulator brushes. If they are worn to short nubs, then a new voltage regulator should fix your initial problem.

The 18.5 volt output of the new alternator may have fried the overload protection relay which is likely behind the removable black plastic piece behind the battery (I am not familiar with the under-hood arrangement of the 190 vehicles), or blown the 10-amp fuse. The overload protection relay is shiny aluminum about 1 1/4" square and 2 1/2" tall with a red plastic top holding a 10-amp fuse. With the engine running you may hear a clicking sound coming from the overload protection relay. Regardless, remove the battery and the black plastic piece to access the overload protection relay. Remove the relay and shake it lightly. If you hear something loose inside, buy a new overload protection relay [Kaehler (KAE)] around $50 online.

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Fred Hoelzle