Bad Alt. Or what?
- Thread starter tjh566
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I'd agree about the heat. Doing as Clay outlined is useful. You can also check the regulator wiring to see if it's all vulcanized. When it's at 12.5 volts, you are discharging the system.
And since it acts up when hot, you could drive to the parts store and let them do a dynamic test on the system.
Good luck.
And since it acts up when hot, you could drive to the parts store and let them do a dynamic test on the system.
Good luck.
You say, "the voltage slowly decreases down to like 12.3-12.5", measured with what? If it's a Ford gauge that would be about and that's what mine showed with a brand new alternator. Stock alternator puts out 130 amps when as less juice is needed it goes back to roughly 87 amps, in underpulleys probably a bit less. I used a ten foot pair of leads I borrowed so I could drive and see what was going on. My guage was lower than I thought it should be but the meter never went below 12.8.
I attached a ground from the alt to the body not too long ago, it got me higher voltages when starting out but then as I drove around for awhile It did the same. Attaching one to the battery isnt really an option since Ive relocated my batt to my trunk for the meth injection system.
I took the alt off a few weeks ago and had it tested it tessted as all good, but to me 12.3-12.5 volts isnt enough... or is it?
edit: I have stock pulleys, No underdrives.
Again, 12.3-12.5 volts is discharging.
Is it possible you're seeing a huge voltage drop in the system? How does voltage at the alternator's charge stud compare to that at the battery itself? If it's more than a couple hundred mV, that's unacceptable to me.
Is your sense wiring still the way it was from the factory? The point of that circuit is to monitor alternator output vs what the regulator remotely senses near the battery. Now that your battery is not near the sense receptor, the alt might not know you're dropping so much current to the battery. Otherwise, it would be kicking alt output up.
Good luck.
Is it possible you're seeing a huge voltage drop in the system? How does voltage at the alternator's charge stud compare to that at the battery itself? If it's more than a couple hundred mV, that's unacceptable to me.
Is your sense wiring still the way it was from the factory? The point of that circuit is to monitor alternator output vs what the regulator remotely senses near the battery. Now that your battery is not near the sense receptor, the alt might not know you're dropping so much current to the battery. Otherwise, it would be kicking alt output up.
Good luck.
blksn955.o
Founding Member
Just asking...
Is either the alt. or brackets painted or powdercoted? The alt. grounds threw the brackets and if there is not a good contact at the alt. or bracket then it could also seem weak.
I found out the hard way when I had my alt. case and brackets powdercoated. They would not allow a good ground. I had to sand down the area of contact to get a good ground. I tested this by running a 8ga wire from one of the alt. case bolts (there are 3 of them) to the strut tower bolt on the pass. side. Started charging correctly instantly and then took off the alt. and sanded the areas of contact.
Is either the alt. or brackets painted or powdercoted? The alt. grounds threw the brackets and if there is not a good contact at the alt. or bracket then it could also seem weak.
I found out the hard way when I had my alt. case and brackets powdercoated. They would not allow a good ground. I had to sand down the area of contact to get a good ground. I tested this by running a 8ga wire from one of the alt. case bolts (there are 3 of them) to the strut tower bolt on the pass. side. Started charging correctly instantly and then took off the alt. and sanded the areas of contact.
Yes I do actually.
All the wiring is the same, I just took the positive battery cable and put it on the distribution box and the negavtive battery cable to the inner fender of the car.
All connections are clean and free of paint.
And Ill test the voltage difference at the battery and alt probly this weekend.
All the wiring is the same, I just took the positive battery cable and put it on the distribution box and the negavtive battery cable to the inner fender of the car.
All connections are clean and free of paint.
And Ill test the voltage difference at the battery and alt probly this weekend.
blksn955.o
Founding Member
might be worth checking your major grounds like block to chassis, batt. to block, and batt. to chassis.
its fast to check and easy to fix.
its fast to check and easy to fix.
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