So I finally got around to doing that whole taurus 130amp alternator swap and e-fan install! Unfortunately it hasn't worked out exactly the way I would have liked. And for reference, I have an '88 Convertible (S4).

So here are the details: I fit the alternator, did all that wiring, and the pulley alignment is perfect, better than any of the other belts by far. I've already shredded 2 belts due to this issue, one Autozone that was 1" longer than stock, a stock size Napa (which lasted longer at least), and I'm on the 3rd now (Napa 1" longer). Also got the e-fan from a nissan quest, fit the shroud to the radiator, wired it up with an e-fan thermostat control switch, and that thing didn't work at all. I just ended up replacing the control unit with a relay, triggered by the ignition signal from some green plug near the battery; does the trick for now, saps power obviously however.

Onto the issue... I'll start the car up (e-fan running, stereo on, no other electronics), drive around a bit, no big deal. Revs just fine, alternator is pushing 14v during driving, 13.6 @idle; all is well. Then I start turning on a few things, such as the interior fan, headlights, etc. and the alternator somehow can't keep up, drops voltage down to around 12, and the belt starts squealing! At this point, the previous 2 belts snapped. I have tried different wiring configurations, different belts, belt tension/pulley alignment, had the alternator tested, and still cannot figure out the issue.

So I've come to the wise and educated RX&Club community for help; any ideas??

 

This is most perplexing as it has the symptoms of a belt being too tight, yet slipping as a result. Did you check the belt tension/deflection per the FSM? Should be ~20lbs of force on the middle, yielding ~1/2". I can't recall the exact numbers, but go by the FSM specs.

 

The belts are a byproduct, not the cause of your problem.
Something ain't right with the alternator/wiring.
That alternator should be pumping out more than 14v under load, but it's not.

 

Duly noted, but I'd think that the Alt would be pumping out max power if it was wired backwards. Please see my album for the correct method to wire a Taurus Alt in a S4

 

I know the belts are a byproduct, sorry if my post wasn't worded as properly as I would have liked. But I'm sure the wiring is good; I tried multiple configurations until settling on the one that I did.

But anyways... UPDATE: The voltage still drops as mentioned unfortunately, but the squealing and such hasn't occurred since I removed the pulley and filed the alternator-side edges down; I thought it could have been rubbing on the casing of the alternator, since the clearance wasn't ideal. Any thoughts?

 

Just to confirm, your alternator is wired like this, correct?


If it is not, wire it as shown in the diagram. The "I" terminal goes to an ignition switched 12v source, while the "A" terminal goes to the battery positive terminal to monitor output activity

If it still behaves the same, I'd suggest taking it to Autozone to be tested, just as a precaution. Sometimes we find duds in the junkyard. Based on all the symptoms, perhaps its bearings are shot? Give it a spin by hand and feel how it turns. It should spin nice and smooth with no clunkiness.

 

Did you put the pulley on the alternator. Is there any chance that your pulley is binding to the alternator body ?