More BS Alternator issues I cant figure out

Doesn't the alt. have (two) inline fusible links? Could one have blown or shorted?


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If the magic smoke came out of the PCM via 18V I am sure it wouldn't be running at 20" of vacuum...

You don't have an O-scope? Come on!!!


My guess is that something is not right with the commanded PWM signal. Definitely pin that harness to the PCM and see if there is an issue there.
 
martyo said:
¿Qué?



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Someone suggested the 18V smoked the ECU... maybe just for the alternator control? who knows...

My thoughts would be if 18V smoked the ECU there would be more issues present. Plus I do believe there is built in protection for this (inline fuses) however Zack states these are fine
 
Limited360 said:
Someone suggested the 18V smoked the ECU... maybe just for the alternator control? who knows...
Click to expand...

That person suggested that he only let some of the smoke out - not all of it.

Limited360 said:
My thoughts would be if 18V smoked the ECU there would be more issues present. Plus I do believe there is built in protection for this (inline fuses) however Zack states these are fine
Click to expand...

Unfortunately it is not that simple.
 
martyo said:
That person suggested that he only let some of the smoke out - not all of it.



Unfortunately it is not that simple.
Click to expand...

Just some of the smoke? hmmmm like frying the 5v signal feed? Should have faults, Zack stated no issues as of now on that front.

18V should be fine on the ECU for a short period of time, not long period. Regardless pin that S#!T out!
 
You said that the alternator is putting out 12.xx volts both at idle and under load, do both alternators do the same thing? If so, you will need to Ohm out the wiring and grounds, as I would tend to lean towards a wiring issue as opposed to a PCM, with a fleet of 100+ police cars, I have hardly ever seen a charging problem related to the PCM, but I have seen plenty of wire that was green on the inside.

And, a load of bad (electrically) connections. Hell, I had one car that was acting flaky, it turned out to have a 70 Ohm difference in the ground from the engine compartment to the interior.

They suck to chase down, but a good DVOM will help you through the mess.
 
The factory alternator cable (with the fusible links) was removed by the owner long ago. It has a 4 ga wire hooked directly to the battery.
Did it put out 18v for a short time??? Honestly I dont know. The gauge did not peg and I wasn't datalogging at the time. Could have been 16v

I know this: I have loaded this tune into 10 cars and they all run perfect. This one will idle nice, but bog heavily under load. All monitors are working fine, as well as sensors.

I am confident my wiring extension to the alternator is perfect. I've removed it and bench tested it!
I will check the Gen-Com wire tonight and swap PCM's if I have to. After that I'm done.
I cant think of anything I did that could cause this.

Since the alternator did not work from the moment I started the car after the swap, there is a high probablility that the alternator itself sent some kind of killshot to the pcm.....thats the only thing that makes some sort of sense.
 
Ill test that wire tonight. Im armed with all the pinouts.

Im gonna miss the opening night of the weekly car show.
GRRRRR
 
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