Alternator blues.

carguy300

Well-Known Member
Joined
Jul 29, 2018
Messages
708
Reaction score
444
Location
East Texas
I need an alternator my 300, cant seem to find one that only has 1 field wire and batt post. They either dont have double pulley or they have internal regulator. Ive ckd the usual places, Rockauto shows to have one that might work, dont know if I trust them. I dont really want to upgrade charging system, im also not sure what amp it should be. I could try to locate a rebuilder and have redone. Anyone with tips or had similar issue, I could use some tips.
 
Just to toss this out there, there's not a lot that goes wrong with alternators. Front bearing, diodes and brushes are the main things to fail. Brushes are easy to replace, front bearings not much harder, although you have to pull the pulley. Diodes involve soldering in new ones.

The other thing is if you have the old alternator you can pull the old pulley and install it on the new one. You'll have to take the back section off to press on the old pulley, but that's easy enough and you can do it in a vise so you don't need a press. You'll need a pulley puller to pull the pulley too. Might be able to rent one of those.
 
Just to toss this out there, there's not a lot that goes wrong with alternators. Front bearing, diodes and brushes are the main things to fail. Brushes are easy to replace, front bearings not much harder, although you have to pull the pulley. Diodes involve soldering in new ones.

The other thing is if you have the old alternator you can pull the old pulley and install it on the new one. You'll have to take the back section off to press on the old pulley, but that's easy enough and you can do it in a vise so you don't need a press. You'll need a pulley puller to pull the pulley too. Might be able to rent one of those.
I know this car sat for a long time, the belts were stuck to the pulleys! I can hear and feel grinding when turning it by hand. There is a rebuilder in dallas area thats supposed to be good and affordable. Last time I had to get one for my other 300 it was easier, that was single pulley and had been upgraded. I want to keep this one correct. How can I find what amperage is rated, ive 45-55-60-90, no idea.
 
I need an alternator my 300, cant seem to find one that only has 1 field wire and batt post. They either dont have double pulley or they have internal regulator. Ive ckd the usual places, Rockauto shows to have one that might work, dont know if I trust them. I dont really want to upgrade charging system, im also not sure what amp it should be. I could try to locate a rebuilder and have redone. Anyone with tips or had similar issue, I could use some tips.
Rock Auto is OK. I like the roundbacks. You're trying to keep your setup looking original? I do well on eBay, or fish locally. How big is the charging wire? That tells the ampacity of your alternator. If its a 12 gauge, get a 30-50 amp alternator. If its a 10 gauge, get a 60. I ran AutoZone alts for some years, simply because they have their warranty. Theirs last a year or so, usually, after making sure its not DOA.

Here;s a crap shoot from eBay for you: 1969 Mopar 46 Amp Alternator 340 383 440 Dodge Plymouth 2875724 OEM Aug 1968 | eBay
 
If you get a reman unit, KEEP your core. Then, find somebody who can rebuild it. Might inquire to the Dallas Mopar Club website for ideas. Of course, there's always NAPA.

CBODY67
 
I know this car sat for a long time, the belts were stuck to the pulleys! I can hear and feel grinding when turning it by hand. There is a rebuilder in dallas area thats supposed to be good and affordable. Last time I had to get one for my other 300 it was easier, that was single pulley and had been upgraded. I want to keep this one correct. How can I find what amperage is rated, ive 45-55-60-90, no idea.
Probably the front bearing. That's not too crazy to change. Pull the pulley, take the brushes out, split the case, pull the bearing and reassemble.
 
Finding one seems to be my problem, mine is round back, single field. NAPA had that style, single pulley for truck?, was 45 amp. Prices $65-$225! Car has electric seats and windows with a/c, I would think at least 60amp. At least I can still get the mech regulator.
 
Probably the front bearing. That's not too crazy to change. Pull the pulley, take the brushes out, split the case, pull the bearing and reassemble.
Where do you get rebuild kits, ive never done this but could sure give it a shot,
 
Well, all of those power accessories do not run all of the time, only when needed. Seems like the a/c cars had a 46amp from the factory? Same alternator went on cars and light trucks. If you're worried about the alternator not having quite enough output, then get a Group 27 battery.

CBODY67
 
Napa did have one but single pulley. I tried to get rad hoses at napa, didnt carry any! Getting harder and harder to keep original look under the hood.
 
I'm surprised that nobody has mentioned this yet. If you find a newer-style alternator that has 2 field terminals, just ground one of them to the case and connect your field wire to the other one.
 
Napa did have one but single pulley. I tried to get rad hoses at napa, didnt carry any! Getting harder and harder to keep original look under the hood.
Here's a key thing to consider. The molded hoses are still available at RockAuto, in various brands as Gates and such. So . . . do some advance planning (about a week) and order them before you are planning to change them. Might end up being about the same price as they would be at the parts store. Or ask the parts store you do business with if they can get the molded hoses for you. You can do the research at RA first, though, for good measure, as to brands and part numbers.

Just because the local parts store might not have a lot of these things in stock does not mean they are "unobtainium".

CBODY67
 
I just used 67 as the year .

1967 CHRYSLER 300 7.2L 440cid V8 Alternator / Generator | RockAuto

Screenshot (90).png
 
My original was seized solid and I thought I’d just replace it, but couldn’t find one anywhere that was the basic lower amp, round back, two pulley. Then I came across a local rebuilder and for $150 it‘s like new.

1693628140205.jpeg

1693628167981.jpeg

1693628190278.jpeg
 
Thats the first ive heard that.

That's exactly what I do w the PowerMaster 95A alt I run now. It's setup as a squareback, and Mike told you exactly right. By grounding that second field lug, you just treat the 2 sets of windings as one, for the simpler regulator used with the roundbacks.
 
I'm surprised that nobody has mentioned this yet. If you find a newer-style alternator that has 2 field terminals, just ground one of them to the case and connect your field wire to the other one.
I think he's trying to keep his ride as original as he can. I only went to a squareback clone because I wanted the extra current for my pusher fan. Before that, I ran a series of short lived VatoZone remans, returning them under warranty as soon as they began to fail. They were crap, but they were roundbacks, seldom remanufactured properly.
 
Here's a key thing to consider. The molded hoses are still available at RockAuto, in various brands as Gates and such. So . . . do some advance planning (about a week) and order them before you are planning to change them. Might end up being about the same price as they would be at the parts store. Or ask the parts store you do business with if they can get the molded hoses for you. You can do the research at RA first, though, for good measure, as to brands and part numbers.

Just because the local parts store might not have a lot of these things in stock does not mean they are "unobtainium".

CBODY67
I actually ordered hoses and oem clamps from moparmall the other day.
 
Back
Top