New alternators either 50 or 60amps?

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gdizzle

gdizzle

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on my 225 \6, no A/C, thinking about replacing alternator but it looks real old. I do not know how many amps it is. But on Oriellys, it is giving me 2 options for my car, either a 1 rib 50amp, or 2 rib 60 amp. In the manual it says the stock Output is 26 +/- 3. Should I be concerned that a new alternator @50a would melt the wires? Ammeter has been bypassed btw.
My current alternator is 2 ribs, however only use 1 rib.

or could I even get the 60amp version? Price is cheap enough.

I am not sure how to tell what Amps my current alternator is running.
 
I'm only guessing (the bottom of your post) you have a 66? This was likely a 35A. What do you mean "ribs" you talking about the field connectors / terminals? Yours would have only 1 field terminal, the other brush grounded

This changed in 1970, at which time Ma went to "isolated field" that is TWO field terminals, and a different voltage regulator

You can use the 70/ later by grounding one field terminal, and hooking the rest up as original

The "squareback" alternators after "sometime around" 72 are superior as they output more power at low RPM

The alternator on the right is the better "squareback"

squareroundcomp.jpg


So far as amperage, I would not necessarily "push" much above 50A

Please read this article

http://www.madelectrical.com/electricaltech/amp-gauges.shtml
 
Over-amps concern depends on how you did the ammeter bypass. If a thick wire (6 awg or larger), within the engine bay from ALT stud to BATT+ (or starter relay thick stud), no worries. If your existing alternator is keeping your battery charged over a week, it is doing its job. But, if you later plan more draws, like electric radiator fan, then go bigger.

Mopar used the square-back thru the K-cars into the 1980's. The diodes tended to fail in FWD cars because of poorer air flow. Some here have installed better Denso alternators, but takes customization. The square-back is usually a direct bolt-in. You just need to ground one terminal, or change to the later Vreg w/ triangle connector. I did and installed it beside the alternator for simpler wiring.
 
Whatever you buy, don't leave the store without them testing it for you. Ran into that problem with O'Reillys once. Took one home, didn't work and they wanted to blame me for hooking it up wrong or whatever. They also tried the "no returns on electrical items". After a lengthy "discussion", they brought out another one, tested it, didn't work. Had one shipped in from another store or warehouse, tested it, it failed too. Gee, I got my refund. Bought a REMY rebuilt. No problems with it. Napa has been selling a "one size fits all" around here lately. You make it work for your application.
 
I think he may be talking about the pulley when he talks ribs.

They come with 1grove or 2grove pulley.
 
yes ribs meant pulley.

Anyhow I took it in to be tested, after several tries of him not connecting it right, he did finally get it set up and tested out fine.

So I drilled out the hole, enlarged it and tapped it to a big bolt 7/16. Then had to jig saw the mounting strap so that the large bolt will fit. Got it reinstalled and tight.

Interesting though, mine just has the battery terminal and then a plug thingy. I noticed that on the alternator there is also a Ground screw which is not connected to anything.
At Oriellys the only way we got it to test was he had to connect the ground to the ground screw. When he tried to connect the ground to the outer casing, the test failed.


Am I supposed to have a wire attached to the ground screw? Or is it grounding through the mounting bracket?

hereis a picture of the alternator, I think it might be original to the car? 1966?
 

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He probably just did not get "through" the whatever all is on the case, paint? I can't tell

Here's the thing..........no need to EVER test an alternator at the parts store, unless it's a new one you want to see "if it might work"

Read some of my posts. You can do all the testing you need on the car

The thing is, there is more than just a good / bad alternator, or regulator.
 
The amount of current which is measured in amperes or amps would not be an issue with the wiring unless you add more accessories and make the alternator work harder. Also it is either a single groove pulley or a 2 groove pulley for less belt slippage with higher amp output alternators.
 
I dont think the case gets grounding anyway as the voltage regulator varies the ground potential on the terminal to regulate the output. ie. 12V in and no ground means its just spinning doing nothing. Give it a hard ground and its now full tilt. give it a medum ohm short and itll put out 13.5V, something like that.
 
pishta said:
I dont think the case gets grounding anyway as the voltage regulator varies the ground potential on the terminal to regulate the output. ie. 12V in and no ground means its just spinning doing nothing. Give it a hard ground and its now full tilt. give it a medum ohm short and itll put out 13.5V, something like that.
Click to expand...

Uh, no, he's got an earlier unit. The VR SENDS voltage to the field, as opposed to controlling the ground, as on 70/ later units. I believe he was referring to the bench tester, which needs a ground just as if it were on an engine. The case, if properly connecting, is that ground.
 
Or you can buy a nippondenso mini universal 50A with internal regulator , and make your own brackets. Dont go with the one wire units. Get one thats the 3 wire. Easy to hook up. Have to fab a bit to make mounts though. Got mine for $85 brand new. Large stud is output on these, the 2 smaller spades are labeled IG and L . You run the other wire from your old alternator. The green wire into the IG spade, remove your voltage regulator on the firewall and connect both voltage reg wires together.

The L terminal in the denso is for a charging fault light in your dash, and is un needed.

Heres mine being mocked up on a 318 with new brackets i fabbed up.

Matt
 

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