Will my wiring handle a 75 Amp alternator?

[Russ]

That Madelectrical article is interesting reading, but I'd be careful about taking what he says to be the absolute factual truth. He's obviously a Chevy guy and his preference is for a Delco alternator. In fact, most everything stated in the article other than the Ohm's Law formulas are his opinion more than fact. He doesn't seem to like the one wire type but talks up the three wire style like Delcos are the only ones like that. Chrysler has used three wire alternators (and the shunt type amp guage) for at least the last thirty years, and the voltage sensing is done at the ignition switch, or split out area, just like he suggests. Chryslers also come in 87,100, and 114 amp capacities, more than the 94 amp Delco. Regarding the higher voltage someone mentioned, is that supposed to be a good thing? Chrysler regulators prevent the output voltage from exceeding 15.8-15.9 volts to keep from damaging the battery, and this is ambient temperature dependent. In higher ambient temps, the voltage will be lower by design. More consistent system voltage? By whose measurements? He also has some examples that are exagerated, or not very realistic. In one of his scenarios he uses as an example a 2.5 volt drop from the alternator to the accessory power take-off point. If you have that much drop you have a problem that should be corrected, and you definitely wouldn't want your alternator to just put out a higher voltage to overcome it. From a couple of 80's Chrysler FSMs, the highest allowable voltage drop from the alternator to the battery is only .7 volts. Any more than that and the FSM says to isolate and repair the problem. This would equate to a less than .7 volt drop in the accessory power. BTW, he mentions that the Delco is cheap to buy, but I got an 87 amp Chrysler alternator with a lifetime guarantee from AutoZone for $37.00. Can't be much cheaper than that. You guys can do what you want to do with your trucks, but I just don't see why you would want to go to the trouble to mount a Delco when you can bolt in a Chrysler that is just as good, and has more capacity.
I do like his article on maintaining and charging batteries. It's under electrical tech heading. Check it out.

[TedWitt]

WHY AUTOZONE?????????????

All I've seen there is mostly junk, and the counter people don't seem to know what you are talking about when you ask for something. All they seem to know is what the computer tells them, on the other hand, most of the people at O'riley in my area (Spring, Tx.) seem to have some mechanical knowledge.

I bought an alt from A zone and put it on my '66, it lasted 1 week, I took it back for another one and it lasted 1 week. Well, I took it back for another one, by this time I'm getting PO'ed, the guy brought out a new one and I told him to test it. He put it on the machine and says it works so I tell him to warm it up. Within 45 seconds it smokes. He brings out another one and runs it on the machine till it gets hot to the touch so I took it. It lasted just over a year. Now I have one from O'Riley, its about 9 years old.

Anything that I've gotten from Azone that's electrical has been a nitemare. I even bought a water pump from them, I installed it and when I put water in, it ran out the weep hole in the pump, yep I was mad. I got my money back and went O'Riley and bought a good one.

In my old age, I've learned not to buy rebuilt anything if I can help it. Now I try to buy NEW, it's worth the money.

Also, a Mopar Alt can be wired to put out 110 volts, try that with a Delco or Fomoco.

[Russ]

WHY AUTOZONE?????????????

All I've seen there is mostly junk, and the counter people don't seem to know what you are talking about when you ask for something. All they seem to know is what the computer tells them, on the other hand, most of the people at O'riley in my area (Spring, Tx.) seem to have some mechanical knowledge.

I bought an alt from A zone and put it on my '66, it lasted 1 week, I took it back for another one and it lasted 1 week. Well, I took it back for another one, by this time I'm getting PO'ed, the guy brought out a new one and I told him to test it. He put it on the machine and says it works so I tell him to warm it up. Within 45 seconds it smokes. He brings out another one and runs it on the machine till it gets hot to the touch so I took it. It lasted just over a year. Now I have one from O'Riley, its about 9 years old.

Anything that I've gotten from Azone that's electrical has been a nitemare. I even bought a water pump from them, I installed it and when I put water in, it ran out the weep hole in the pump, yep I was mad. I got my money back and went O'Riley and bought a good one.

In my old age, I've learned not to buy rebuilt anything if I can help it. Now I try to buy NEW, it's worth the money.

Also, a Mopar Alt can be wired to put out 110 volts, try that with a Delco or Fomoco.

It was Sunday afternoon and I had to have my car for work the next morning, and Autozone was the closest place that had what I needed. If it had been different I would have just replaced the brushes in the alternator. That was two years ago. I sold the car last month and hadn't had any problems with the alt. AutoZone must have different rebuilders for different parts of the country. I've bought a few things from them and have had good luck. The only problem I've had with them is I bought an oxygen sensor for my 87 Diplomat. The box looked perfect and I almost payed for it without looking at it, but I decided to open the box to make sure it was the right thing. Good thing I did because it had an old used one in the box. Not really their fault, I guess.
I do agree with you on one thing, the typical AutoZone counter person is not very knowledgeable about cars. O'Rileys stores are fairly new around here and I've never bought anything from one of them.

[wittyhoosier]

110 VDC? Not very useful except for lights or resistance heat, but still really cool! I guess you could figure the 60hz rpm if you knew how many poles, and took out the rectifier. How do you wire for 110?

[TedWitt]

I'm not really sure how, but my mom had one on a briggs n straton motor on her boat dock for lights, I think my stepdad wired it, he's been dead for about 15 years now, I do know it was a 2 wire alt, I have an old one with the bushings about gone, I may see if I can figure it out without frying the diode body. It would be really good for the deer camp, huh.

[MountainMoparRobin]

Thanks Russ,
I was more than sure Mopar had the same or better, was really confused, especially when we all got together sunday and we all had 3 wire Altenators, 120amp, 110amp, and 80amp, I thought I was loosing it