Need Opinions on Alternator

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DakotaDuster

DakotaDuster

"I'm all in."
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Okay, so I'm in need of a new alternator and I ordered this Powermaster unit for my 74 Duster w/360 the other night...

http://www.jegs.com/i/Powermaster/713/17519/10002/-1

I have some questions after doing some reading about the Chrysler electrical systems. It seems as if they aren't very robust and a higher amperage unit can cause issues. This Powermaster unit is a 90 amp. I'm not sure what the alternator that I took off is because the part # sticker is half faded, so I can't look it up. Is the likely hood high that the 90 amp unit is going to cause electrical issues?

Along the same lines, I don't plan to run a ton of electrical accessories. No radio, no A/C, no electric fuel pump. I do how ever plan to upgrade the headlights, the fuel cell I'll be installing has a GM sending unit(0-90 ohms), and I plan to sooner than later go with a classic dash instrument panel and gauges kit. Is the 90 amp unit enough or maybe too much? Any help or info is appreciated.
 
Well it is very likely to be "too much" IF you still retain the factory original wiring. The bulkhead connector, ammeter and wire size used in the charging circuit is very limited, and was never designed for much above 40A. "Ma" knew this and implemented what has become known as "fleet police taxi" wiring, and which in some part BYPASSES the bulkhead connector.

CERTAINLY you need to read this article:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

Also if you do eliminate the ammeter, there is an thread here on FABO about converting the original meter to a voltmeter. Unfortunately the "Sunpro" meter used does not seem to be available, any longer. However, this might gives you ideas

http://www.forabodiesonly.com/mopar/showthread.php?t=119480
 
Thank you for the quick reply and the links. Just a quick glance(watching the fights) at the two links, it's a lot of things I most likely won't understand very well. Electrical and I don't mix very well. I'll have to read them when I can focus completely on them... And most likely several times lol.

Unfortunately, I'm not entirely sure what all is original and what isn't. The car is still relatively new to me. I haven't even owned it a year yet. Still learning so much about it. I know the previous owner had done what to me is quite a bit to the car, but some of which seems to have been Jerry rigged... Including the little 3 gauge cluster where only the oil pressure works but no lights to the gauge.
 
The alternator rating is only a manufacturer's claim -usually an approximation of maximum output (which only occurs at high alternator rpms). Sometimes a higher output alternator will do better at low rpm as well, other times they will do worse. It depends on how the extra output was achieved.

In any event, when all is working well, the alternator only puts out current based on demand.
The danger of overloading the wiring is when there is a bad connection (which will get hot), wires grounding out, or extra loads. Lets say for example the battery is dead and the car gets a jump start. Then its driven at highway speeds. Potentially your new alternator could put 90 amps through the ammeter as it tries to recharge the battery. Thats more current (flow) than the ammeter and wiring was meant to handle, never mind possibly deteriatoriated.

The a-body headlight wiring is particularly weak. They used the absolute minimum wire size needed. For that alone, please consider a relay system. You can buy them premade. I've personally had headlight circuit breaker flicking off on the highway, and in another a-body the connector to the headlight switch start to melt.
 
Thank you for the information. Yeah I've been reading and re-reading topics on headlights. Making sure to pay close attention to what slantsixdan has to say about things in particular. I need to see if this car has the ammeter bypassed. Next do more research on headlights and relay kits and how to properly install all this. As I said, electrical is not my thing so I get really anxious about electrical projects. Especially after being under the dash when changing out my speedo cable. Who knows how Jerry rigged the wiring is...

The car won't be back on the road for several months, so this isn't something I'll rush into. Thanks again for the info!
 
There are plenty of ways to approach the wire around. I build wire around and headlight relay kits. If there is anything I can help you with, shoot a question.
I'd definitely jump the bulkhead connectors and upgrade the charging route.

A 90 amp alternator is plenty for a car with limited electrical loads. One of the more important aspects is the low rpm output. The dim light syndrome our mopars suffer from is pretty routine.

Good luck with it.
 
Well I feel bad hearing all this Mopar bashing, could it not be that most cars with 40 some year old wiring are in need of an upgrade?
Also, Dakota, I have not even done the Crackedback headlight relay yet and from the reading I have done, DO IT!, I am, and I have read not one single complaint from his system, how often does that happen? And don't be afraid about not being an electrical engineer, I hear his instructions are about foolproof. Mattax explained it well, Crackedback will help.
 
Thank you Phil, I appreciate the positive comments. The instructions were a team effort with Hemitheus and 6pk2goDemon. We tried to make them as comprehensive as possible.
 
Thank you for the input guys. Crackedback, I did take a look at the thread with info on your relay kits. I don't see why I WOULDN'T go with your kit when the time comes. It is continually brought up when theres mention of headlight upgrades. As far as the install goes, I do have several Mopar buddies around to lean on if need be... and most likely will, but I do like to do things myself if I can.
 
You need an alternator. That's my opinion.
 
I got the alternator a few days ago, but here's the card for the unit I bought.

12645122_10153836328366730_4969723169538316800_n.jpg
 
If it really puts out 67 amps at idle, do some sort of wire around solution.
 
DakotaDuster said:
What exactly do you mean by wire around solution?
Click to expand...


Just add a 8 gauge or larger wire from the charging terminal on the back of the alternator directly to the battery or the battery cable on the starter. Your amp meter won't be accurate anymore, but you won't have to worry about frying the stock wiring.

I'll be using a 220 amp alternator and will be using 0 gauge battery cable from the alternator to the starter.
 
crackedback said:
If it really puts out 67 amps at idle, do some sort of wire around solution.
Click to expand...

Well that's the question, isn't it.
At what rpm and voltage where each of those numbers measured?
If they went through the trouble of testing and measuring, which they probably did, why not provide the full info. ?
Thats kindof way too vague, A stocker can idle down at 450 rpm and some hot rod owners are happy at 1000 rpm. Also by changing the load/voltage, the output will change.
 
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