Voltage spike...?

[454Man]

At the alternator
The voltage fluctuates from 13.8-14.5.
Tried the jumper to the alternator case no change

[454Man]

This time around I drive 17 miles and the readings I just posted were the results at both Batt and alternator

[454Man]

Alternator voltage is fluctuating between 13 and 15.3 under load. I tired the reg wire to the charging post. Still the same thing. . Some reason I'm thinking it's a ground issue idk

So, measured at the battery, output voltage fluctuates between 13 and 15.3, using the headlights for the load.  The alternator's 4-ga charge lead is connected directly to the battery positive post, and you connected the regulator #2 wire to the output post of the alternator.  Correct?

Measure alternator output voltage directly at the alternator output stud.  Connect a temporary jumper between the alternator case and the negative post of the battery.  Any change?

Do you have an inductive DC ammeter module for your Fieldpiece meter?

I did connect the #2 reg wire to the Batt out post on the alternator.

The alternator's 4-ga charge lead is connected directly to the battery positive post, and you connected the regulator #2 wire to the output post of the alternator.  Correct? Correct sir just like you say :-)

[bd]

Is the charge voltage constant or fluctuating at constant engine RPM?

If it's fluctuating, it sure sounds like a regulator issue or connection issues inside the alternator.  A properly functioning solid state regulator should stabilize voltage output at about 14.5 volts.  It may have been damaged when it went full field.  What kind of warranty do you have on your alternator?

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Although there still could be a wiring problem, you may have to take systematic voltage drop measurements to find it.  Best approach would be to pull all the fuses again to eliminate all fused accessory circuits.  Could prove quite tedious.  Frankly, I would start with the alternator.

[454Man]

Honestly my thoughts are as yours. I figured it was damaged by the old battery cable. I'll cut open the old battery + wire tomorrow. I just bought the alternator a fee months back... ButThe thing that sucks is I bought it from Orielys AV BD know they will put it in the tester and say it's still good. I'll have them test it under extreme load while it's in the truck. Got any ideas on how this thing can go bad quick with out causing a seen at the parts store? I'm game :-)

[454Man]

Is the charge voltage constant or fluctuating at constant engine RPM?

Yes you can hear it clear with my loud pipes :-) if I had a tach(it burnt out due to this issue... It would fluctuate as well. Burnt out as in I smelt it and clipped the writes going to it. Not grounded out. It just couldn't handle the high volts going to it.

[454Man]

Well it tested good so I'll have to try buying a new one. Other wise evenings good

[diphthong]

There is quite a lot to read through here, is this still an active post and is the problem still presently the same problem as your first post?

If yes, what year is your truck? and does everything running through the fues box lose power when the problem happen?

[454Man]

Voltage spike is gone. Thanks to these good guys. Nothing lost power inside.. Just saving for a good name brand alternator at this point