Diagnostic of 28AMP failure VRR check confusion?

[John OoSTerhuis]

Stator dynamic voltage test: .5 V each combination of pairs on the stator side of the 3P connector

Paul. Rereading the thread and seeing the above, assuming that's only .5 volts AC, and in light of all the other testing to date, I suspect the 2P black and white wires circuit also. I'd do some continuity and resistance testing of them. You need to start with battery voltage getting to the 2P. If in doubt you could even jumper power directly to test by bypassing.

 

[Oldschool1]

John,

I tested it again. Then found 11.8 to 11.95V at the 2P connector (black to white wires). I really can't explain the difference in findings from before to now - but first i'll suspect operator error (the logical choice) First i though it was intermittent - and maybe it is, hence an open in a wire. But I was able to verify the voltage remained present with 3 plug/unplug cycles of the 2P and also wiggling the So the exciter voltage is present.

With exciter voltage present battery voltage is still 12V at battery, with existing VRR and STOC test VRR. 2P connector shows 3Ohms resistance from black to white - so should be ok.

So i think this confirms the alternator is DEAD, even though resistance and ground checks for the 3 yellow wires from the alt check out.

Maybe time to just start preparing for the 40AMP, if its going to be involved.

 

[John OoSTerhuis]

Anyone else want to chime in...? Opinions... guesses?

 

[Oldschool1]

Well I haven't had much time to think about this - other than "I feel another agonizing ST year coming".

Given the latest thougt is that the Alt failed, but all electrical static checks show good?? , what is the typical failure mode of these (opens in 1 or more of the 3 yellows).

Ok one other hypothesis: The althernator is not turning? That certainly would support the electrical checks. What is the propability of this? One one of my other posts I had a recenct UNDMN (unidentified noise driving me nuts) which as i probed around for many weeks thought it may have been coming from the back end / transmission area of the engine. It was a click - could have doubled for a valve out of ajdustment type sound or mechanical interference.

Thoughts on this?