Alternator Question

[JM_ART]

I’m still learning about my ‘68 New Yorker. I guess I’ve been a slow-mover regarding some of the things I want to accomplish because I’m devoting more time to reading about the car, it’s parts, and likely updating/upgrading paths.

One of the parts I’m looking at is the alternator. Here’s phots of the casting number and what I think is the part number, which is on the upper side of the rear of the alternator.

Am I reading this as an alternator made in 1963? It has only one field connector on the back. I don’t see any relative information on the car’s window sticker re: the alt. Is this a 26 amp unit? Seems like it would be a bit low with power windows, locks, drivers seat, A/C, a rear defroster, and am/fm multiplex radio optioned, doesn’t it?

Im asking because I don’t know how many amps this alt should be putting out. If it’s a low amperage unit, I’d like to replace it with a higher amp unit (nothing crazy, but certainly better than 26 amps). Your thoughts and/or guidance is always appreciated. Thanks!

 

[live4theking]

In the FSM on page 8-78 it shows that cars equipped with AC should have a 44 amp alternator. The special equipment one that is listed is only for 51 amps. Anything more than that I would be concerned about overloading the wiring. Remember too that you won't be running all of these systems at once.

 

[CBODY67]

The casting number identifies that particular casting only. The stamped number identifies the particular unit assembly, which is the ID number you'll find in the parts book and other similar publications.

The "first gen" Chrysler alternators were all pretty much the same, with variations in output amperage. The dual-fleld models did not happen until many years later, but can be adapted to the earlier models with minor "work". At this point in time, it's very possible that the alternator on the vehicle in not the one it came with from the factory. A shop can test it for its output, if desired, so you know where things are at. Note too that you'll need to clean the battery terminals BEFORE such a test for best results.

The FSM will detail what amperages came on which models. A main consideration was "air conditioning", rather than any other power items (PW, PS, etc.). As for the a/c option, it also resulted in some different drive ratios of the alternator and such via pulley sizes.

Enjoy the discovery!
CBODY67

 

[JM_ART]

In the FSM on page 8-78 it shows that cars equipped with AC should have a 44 amp alternator. The special equipment one that is listed is only for 51 amps. Anything more than that I would be concerned about overloading the wiring. Remember too that you won't be running all of these systems at once.

Thanks for the response. You’re right about the number of accessories not being used simultaneously. And thanks for pointing out the FSM reference. I’ll take a look at it this morning.

 

[1966newport]

will only put out the amps that the system is using

 

[Big_John]

Over the 52 years this car has been around, it's very possible, almost probable, that the alternator was replaced with a rebuilt unit somewhere in its life.

The rebuilders don't care about date codes, it's all about if it interchanges or not.

So, here's the thing... Does it do the job? If so, leave it alone and go enjoy the car.

 

[JM_ART]

Over the 52 years this car has been around, it's very possible, almost probable, that the alternator was replaced with a rebuilt unit somewhere in its life.

The rebuilders don't care about date codes, it's all about if it interchanges or not.

So, here's the thing... Does it do the job? If so, leave it alone and go enjoy the car.

I appreciate what you said, John, and thanks for responding. I figured when looking at it that its likely a rebuild. Although, looking at the original owner’s maintenance log (which goes back to 1973), I now see the original was replaced with one from a parts car, and later replaced again in 1976 (the log isn’t specific as to whether it was a new one, or a reman unit). I guess I’ll have to test it’s output. But, since there’s no maintenance activity logged for the alt after ‘76, I have to assume it’s a 44 year old unit and likely ripe for replacement.

Right now I’m trying to establish baselines so I know what I’m dealing with, and whether it will need to be updated or upgraded. Right now it’s doing what we need it to do, which is not much because we’re not driving it pending a state safety inspection after rebuilding the front end, new brakes, and new leaf springs... all in the near future-I hope. For now we’re focusing on the engine compartment. And I have mysteries from the 2 previous owners (funny wiring at the bulkhead and behind the dash, an unknown brand electronic voltage regulator, etc. ). The cars alt is just one other thing I need to learn about, so I know whether I can leave it, or update it.

 

[70bigblockdodge]

If it does not pulse the diode set is good.
If it works the field is working.
Change the brushes and it will be good for a long time.

 

[JM_ART]

The casting number identifies that particular casting only. The stamped number identifies the particular unit assembly, which is the ID number you'll find in the parts book and other similar publications.

The "first gen" Chrysler alternators were all pretty much the same, with variations in output amperage. The dual-fleld models did not happen until many years later, but can be adapted to the earlier models with minor "work". At this point in time, it's very possible that the alternator on the vehicle in not the one it came with from the factory. A shop can test it for its output, if desired, so you know where things are at. Note too that you'll need to clean the battery terminals BEFORE such a test for best results.

The FSM will detail what amperages came on which models. A main consideration was "air conditioning", rather than any other power items (PW, PS, etc.). As for the a/c option, it also resulted in some different drive ratios of the alternator and such via pulley sizes.

Enjoy the discovery!
CBODY67

Thank you for telling me all of that. It’s appreciated. It’s definitely all about discovery with this car (ha!), and I always come away from reading these forum posts with much more knowledge than I had before. It’s a process, and I’m checking the condition of things underhood, making references with the first owner’s logs, and trying to get a bead on what needs to be done.

This definitely isn’t the factory alt unit. It was replaced twice in 1976, per the first owner’s maintenance log. No further mention of alt work from ‘76 through 2000. It’s up for grabs as to how old this unit really is, or when it was put on the car.

 

[Polara_500]

What they're saying is newer ain't always better. Much of the new/rebuilt crap you get nowadays will have a much shorter life span than what's currently on the car as long as what's on the car is working now. "If it ain't broke, don't fix it." Gone are the days when you can take your starter/alternator down to the local rebuilder and get a quality rebuild of your old unit in a couple days.

 

[Big_John]

I have to assume it’s a 44 year old unit and likely ripe for replacement.

It really depends on the mileage after 1976.

Here's what goes on the Mopar alternators and why they are replaced... In no particular order, brushes, diodes and the front bearing. Yea, anything else can fail, but these are the biggest offenders. ALL can be changed pretty easily, the only "special" tools are a puller for the pulley and a soldering iron for the diodes. It's all pretty easy too.

The problem is that ANY replacement probably won't be as good as what you already have. That includes the new stuff (in my experience and observation). "New" rebuilds are questionable at best.

 

[The Goose]

Gone are the days when you can take your starter/alternator down to the local rebuilder and get a quality rebuild of your old unit in a couple days.

Polara is right but he should’ve said “easily” because with a bit of looking you can and will find an old school shop that will rebuild your unit for a bit more money than the off the shelf junk from zippy zone. There are two types of shops the big turn and burn industrial rebuilders (avoid these) and small rebuild shops that work with all the local shops. These guys are usually plugged into the hot rod scene and any hot rod type shop can help you locate them if you’re having trouble in your search. If you have to buy right now keep your core for rebuild at a more convenient time. The mom and pop shops are going away because next gen has no interest in taking over but they’re out there. They’ll only survive if we use them...

 

[JM_ART]

If it does not pulse the diode set is good.
If it works the field is working.
Change the brushes and it will be good for a long time.

The few times we’ve had her running it seemed to be working okay. No idea of its output, or whether it’s consistently, so we’ll want to test it.

 

[JM_ART]

What they're saying is newer ain't always better. Much of the new/rebuilt crap you get nowadays will have a much shorter life span than what's currently on the car as long as what's on the car is working now. "If it ain't broke, don't fix it." Gone are the days when you can take your starter/alternator down to the local rebuilder and get a quality rebuild of your old unit in a couple days.

Oh, I definitely understand there’s a lot of variance as to the quality of remanufactured parts; some are better than others, and some are best avoided. I’m learning that can extend to “new” parts as well.

Fortunately, I have a friend who knows some of the best rebuilders in this area. Having a quality rebuild of the unit is certainly an option.

 

[live4theking]

I appreciate what you said, John, and thanks for responding. I figured when looking at it that its likely a rebuild. Although, looking at the original owner’s maintenance log (which goes back to 1973), I now see the original was replaced with one from a parts car, and later replaced again in 1976 (the log isn’t specific as to whether it was a new one, or a reman unit). I guess I’ll have to test it’s output. But, since there’s no maintenance activity logged for the alt after ‘76, I have to assume it’s a 44 year old unit and likely ripe for replacement.

Right now I’m trying to establish baselines so I know what I’m dealing with, and whether it will need to be updated or upgraded. Right now it’s doing what we need it to do, which is not much because we’re not driving it pending a state safety inspection after rebuilding the front end, new brakes, and new leaf springs... all in the near future-I hope. For now we’re focusing on the engine compartment. And I have mysteries from the 2 previous owners (funny wiring at the bulkhead and behind the dash, an unknown brand electronic voltage regulator, etc. ). The cars alt is just one other thing I need to learn about, so I know whether I can leave it, or update it.

My car hasn't been driven since 1980, 35 years. I probably drove it for two years before I heard what I suspected to be being whine. I took it to a local rebuild and returned it to service after he went through it.

Fortunately, I have a friend who knows some of the best rebuilders in this area. Having a quality rebuild of the unit is certainly an option.

This is what you do if you want an insurance policy.

 

[70bigblockdodge]

If you have a trusted rebuilder then you already have your answer. Just have them go through it for piece of mind or be cheap like me and run it to bitter end.

 

[Wildaugust]

If it works and isn't noisy, if you can drive your car at night, then park, shut everything off and not have any problem cranking the engine when you go to start it again, I would leave it. If, as mentioned, the lights don't pulse when the engine is running and if it doesn't look or smell like the windings are running hot/burning, then I would leave it. If you know you have a good battery and you are getting 14 to 14.5 volts at idle, then.... These are the things I go by anyway.

I have never had to do anything except brushes and bearings in any of my alternators, Mopar or Ford. Sometimes I've just opened them up and greased the bearings. These old alternators last a long time.

 

[JM_ART]

My car hasn't been driven since 1980, 35 years. I probably drove it for two years before I heard what I suspected to be being whine. I took it to a local rebuild and returned it to service after he went through it.


This is what you do if you want an insurance policy.

Having a good, rebuilt unit on the shelf as a backup would be a good idea.

 

[JM_ART]

What they're saying is newer ain't always better. Much of the new/rebuilt crap you get nowadays will have a much shorter life span than what's currently on the car as long as what's on the car is working now. "If it ain't broke, don't fix it." Gone are the days when you can take your starter/alternator down to the local rebuilder and get a quality rebuild of your old unit in a couple days.

As of to emphasize your point, the maintenance log says the original alternator on this car apparently lasted 80,000 miles before going south. I wouldn’t say all the rebuilders are gone, but it does seem like you have to know someone to find a good one, or at least tell you who to stay away from.

 

[Gerald Morris]

What they're saying is newer ain't always better. Much of the new/rebuilt crap you get nowadays will have a much shorter life span than what's currently on the car as long as what's on the car is working now. "If it ain't broke, don't fix it." Gone are the days when you can take your starter/alternator down to the local rebuilder and get a quality rebuild of your old unit in a couple days.

I went through 2 "DuraBLAST" alternators from VatoZone in about 18 months before getting the current mediocre unit I run with. Its kept my big Exide battery charged decently for over 3 yrs now and is nominally rated as a 60 amp unit, which is correct for my 66 Newport. The ONLY reason I have for staying with this crap brand is that their warranty is VERY GENEROUS. The Vatos KNOW what Kwalitee their rebuild sweatshops across the Border puke out, and they cheerfully replace alternators as soon as folks come up to the counter with something sporting their label.

Be this as it may, I'm likely to get a Tuff Stuff 9509 series alternator. These turn out 130 amps, using their external regulators. I can and will easily wire the charging harness in such a case, going to #4 AWG at miimum, though #2 AWG will be needed if the length of the alternator lead to the battery exceeds 6' 3.5". I probably will go with #2. Overcurrent protection becomes a little more involved at higher ampacity, given the dearth of fusible link WIRE greater than #10 AWG, which makes things a little more complex. I probably would make a carefully measured fusible "cable" consisting of FOUR #10 AWG Hypalon insulated fusible link wires, all exactly 7 inches long, allowing for 1/2 inch of bare conductor on each end, to be soldered together. One can also purchase slow blow fuses, which often serve as "fusible links" in more modern automotive circuits than mid 1960s. Big current requires big safety, and this doesn't scale linearly.

So, unless there is a CLEAR NEED for high amperage power generation, it is BEST to stay within OEM specified limits. As much as I enjoy electrical experimentation, I must retain UPPERMOST IN MIND my FAMILY'S SAFETY with ALL design modifications. Others may do as their conscience dictates.

 

[JM_ART]

I went through 2 "DuraBLAST" alternators from VatoZone....

Thanks.