Page 1 of 1

Alternator / Ignition / Ballast resistor questions from a dummy

Posted: Tue Jan 01, 2019 10:22 am
by Aquaholic
Happy New Year all!

One of the items on my 'to do list' this Winter is to obtain a spare/replacement alternator for our 1989 32 Sedan. During our journeys last year we noticed that the one alternator did not seem to be putting out adequate amps. In researching and looking for a replacement several questions have come to me.....Hoping to get some good input.

1) One wire -vs- two wire? my current set up are two wire alternators. I believe it reading up on this that the conversion is simple to go to one wire units. Any reason NOT to do this?
2) Ignition and ballast resistors. Ok...yes, I told you already i am a mechanical dummy. How do i know/verify whether I have electronic or points ignition? AND, I have read some about eliminating the ballast resistors but am not sure how this is accomplished?

Unfortunately, our vessel is not close to home (currently on hard in Demopolis Al at Kingfisher Marina) and I do not really have time/ability to make it down to the boat to work on much until late May when we plan to go back down and take her down to the Gulf. I am strongly considering hiring a reputable mechanic to make updates.....any suggestions in that area?

Thanks!

Re: Alternator / Ignition / Ballast resistor questions from a dummy

Posted: Tue Jan 01, 2019 9:04 pm
by javalin390
Here's some input/experience from my boat. My alternators were updated to the one wire type by the previous owner ( my boat has Chryslers in her). Worked flawlessly for five years now. Ask any hot-rodder/old car buff, the one-wire is the only way to go. I'm guessing that since you are asking about ballast resistors, the yours has Chryslers as well. Being an '89, is most likely has electronic ignition. The dual ballast that is found on Chryslers were used on both the old points and the electronic, giving a full 12 volts to the ignition for cranking/starting, then reducing it when the key is released to the "RUN" position. A Chrysler electronic module cannot continually run on 12 volts, it will burn up the module, hence the resistor. Not sure about the Mallory or Pertronix systems, But I do know the GM electronic (often called the HEI) is designed to run a full 12 volts at all times, the Run wire from the key switch goes directly to the module. There are lots of posts on this site regarding ignition upgrades, just look under the engine/drivetrain link, these range from all out distributor replacement, to simple upgrades, such as modifying an old existing Chrysler electronic to a GM HEI module while keeping the original Chrysler distributors. Choices are endless ! Keep in mind, if you decide to leave it original, I always keep a couple spare ballast resistors on board just in case. And also, ballast's for these are marine specific !! Unlike the units found on a Dodge pick-up or Plymouth sedan, the ceramic is sealed in the back to prevent explosion hazards in a boat. Look around on the web, I do know the Mopar to GM HEI conversion can be found on Car Crafts and Hot Rod's web sites, it's actually pretty simple, thinking of doing it myself. Hope this helps.

Re: Alternator / Ignition / Ballast resistor questions from a dummy

Posted: Wed Jan 02, 2019 10:43 am
by Fastjeff
Ditto on the one wire alternators. (The only knock on them is you sometimes have to 'boot' the throttle to get them going, or they may drop out after long, slow idling. Another 'boot' and they're back at work.)

One of the wires going to the old voltage regulator will be Hot in key ON. You need to tape this off. If you someday go to an Edelbrock 1409 carb, this wire is perfect to operate the electrical choke.

Jeff

Re: Alternator / Ignition / Ballast resistor questions from a dummy

Posted: Sun Jan 13, 2019 7:17 am
by Aquaholic
Thanks for the input guys. Based on what I am hearing/learning I think that I will go with the "If it aint broke why fix it" strategy and keep it original. We definitely do carry xtra/spare ballast resistors on-board.

Re: Alternator / Ignition / Ballast resistor questions from a dummy

Posted: Thu Jan 17, 2019 3:16 pm
by bill
BigM
Food for thought. 8-)
The original 5 pin ignition modules needed a ballast resister in order to reduce the voltage to the unit the newer 4 pin do not. They run on 12 volt.
The old two ballast resister system was used to reduce the voltage to the module and the coil. If you switch to a four pin module you can use a single ballast resister for the coil. I have switched both engines over to a 4 pin module and you use the same 5 pin female plug and left the two ballast resister in place. Wont hurt anything. Four pin modules are easier and cheaper to find. :) The marine and automotive modules are the same. Not to be confussed with the ballast resister which are the marine version only. Sealed with no exposed resister coil the glows red hot. (like a toaster) :shock:
bill

Re: Alternator / Ignition / Ballast resistor questions from a dummy

Posted: Sun Jan 20, 2019 7:18 am
by Fastjeff
..."The original 5 pin ignition modules needed a ballast resister in order to reduce the voltage to the unit the newer 4 pin do not."

I do not believe that is correct. In fact, I know that running the switch box on a full 12 volts will cause it to fail after a period of time. Both of mine did, and within hours of each other! Talk about well-designed failure rates.

Mopar went a bit nuts when they designed this system, using TWO reduced voltage circuits to power the switch box. The 5 pin modules use both circuits where the later (more sensible) 4 pin modules utilize only one.

Jeff

Re: Alternator / Ignition / Ballast resistor questions from a dummy

Posted: Wed Jan 30, 2019 12:35 pm
by bill
BigM
This is the wiring diagram for the 4 pin ECM. It shows the ballast resister is only used for the coil.
Pin #3 is not used.
On the 5 pin ECM pin #3 is feed from the 5.0 ohm side of the dual ballast resister.
On both ECM's Pin #1 is feed from the ignition on side of the ignition switch at full battery voltage.

bill
thank you gofastforless.com

https://www.google.com/imgres?imgurl=ht ... iact=mrc&u

NOTE: :D
If you click on the pictures on the right you will see the wiring for a five pin ECM.