4cyl 93 mx-3

Vehicle loses electrical power. Alternator has been removed and tested good on3 test includingdiode.
However when watching the electrical in vehicle with voltage meter attached at the battery sometimes it runs great and charges at 14 volts.
When it starts acting up it reads between 6 and 8 volts and rpm meter stops respondingdue to low power.Note actual enginerpm doesn't change the rpm needle just drops out.
Pulled all fuses and relays except for engine computer fuse and fuel pump fuse and relay trying to isolate the problem.
However the power problem still occurs. If you pull off the battery cable theengine still runs until you put some other load on the electrical system. Like brake lights, head lights, or fans. I still suspect the alternator is failing intermitently. ANy suggestions?
I tried a different battery as well. Charged battery full and battery still dies to 8 volts in a matter of driving 30 minutes or less.

I don't want to buy an alternator and not need it. Especially if noone going to refund it.
It may be a short somewhere. Sometimes shorts come from inside alternators.

Extremly frustrated as both cars I own have broken down in one month. The other is a ford focus with defective valve seats that somehow fall into the cylinder and smash around causing all kinds of fun. Not a good month.

Any suggestions would be appreciated !

 

Wow not everyone post at once! Anyway Found that mx-3 4cyl has same alternator as kia sephia 94-95 . Grabbed an alternator at Junkyard for $23 and it seems to be working well so far. Guess the alternator was failing intermittently. SO there you have it.