Brain teaser stumpped

[richterjustin08]

98 disco le, with 174k on it. Yesterday I was driving down road doing 65-70 and my speedometer and tachometer are jumping around like crazy, all the lights go dim, and the ac slows down.. as soon as I turn the ac off Nd the whole truck jumps up with a while lot of power and is working fine... Alternator is good, I check and grinder all connection meaning , the ground that goes from battery to frame, the one that goes to battery to starter, and even check the connection to the alternator and its fine... I started up turned the ac on, and still same thing..... Any idea anyone.....

 

[Disco Mike]

Sure, your alternator is most likely failing, go have the charging system tested at a local parts store, running voltage has to be between 13.6 and 14.4 volts.

 

[richterjustin08]

Will do mike... I'll get back and let u know sir... Worst case what's a good website on s good price for one ..

 

[richterjustin08]

Alternatpr is putting 13.9 out still when I turn ac switch on the tachometer drops a 1000 down,

 

[richterjustin08]

It was the alternator everyone, the regulator is out, thanks mike