Magnum 318/5.2L Swap (Carbureted) - Stock serpentine alternator set-up?

gwmax65

Magnum V8 Mopar
Joined
May 17, 2013
Messages
120
Reaction score
78
Location
Utah
Hello, got a 318 Magnum motor from a 1997 Dodge Van, converted it to a carbureted motor, but still sticking with the serpentine belt system without A/C. This motor was recently dropped into a 1965 Plymouth Valiant, and the only hick-up I am at now is figuring out how to wire the alternator & not fry my charging system with it's high-amp rating. I believe it's a 90 amp alternator (or 136 amp), and I know back in '73 everything went to electronic, so you could do an electric voltage regulator conversion to be able to run a 60 amp alternator. I don't believe that set-up would work well with this stock magnum alternator, and have heard you need the computer to operate the alternator. Has anyone out there wired up a stock magnum serpentine belt driven alternator in their early A-body/old Mopar? Hoping to have this running in a couple weeks. I do not want to change the whole belt/pulley system to the LA old-school style just because of an issue with an alternator.
 

Attachments

  • IMAG0413.jpg
    41 KB · Views: 2,195
  • IMG_0466.jpg
    45.6 KB · Views: 1,132

318willrun

Utube channel 318willrun
FABO Gold Member
Joined
Sep 13, 2013
Messages
20,524
Reaction score
25,324
Location
I'm here
I, too, wondered about this question.....
 

mderoy340

Well-Known Member
Joined
Aug 2, 2012
Messages
2,596
Reaction score
1,490
Location
Melbourne FL
alternator can be wired in using a mopar electronic voltage regular. Make your own harness and your good to go. Add a fusible link to the alternator to protect chassis wiring.
[ame="https://www.youtube.com/watch?v=utXjxwPAcHk"]External Voltage Regulator kit for Dodge - Chrysler - Jeep, kit improvements - YouTube[/ame]
 

Attachments

  • dodge alternator wiring.jpg
    44.6 KB · Views: 1,389

gwmax65

Magnum V8 Mopar
Joined
May 17, 2013
Messages
120
Reaction score
78
Location
Utah
Thanks for the info! Will post pics of whats happening with the wiring, think I got it figured out.
 

gwmax65

Magnum V8 Mopar
Joined
May 17, 2013
Messages
120
Reaction score
78
Location
Utah
Late update: Got it figured out nearly a year ago haha! Bought a 70's-80's style Mopar voltage regulator new off eBay. Also bought the correct voltage regulator connector from the same place. I used a battery tester to test continuity on my factory alternator wires to figure which one out of the two wires was witch. Anyways, just got a 12 gauge wire going straight to my battery and to the alternator. Guess it doesn't matter what amp your alternator is, if you already have a fusible link from factory where all the connections are at the firewall, you'll be safe. So you got 2 FLD posts on the alternator, and a blue + green wire. It doesn't matter witch side you hook it up to between the 2 FLD posts on the alternator, and when you kick your ignition on, it kicks the voltage regulator on, witch then will make a connection between the 2 FLD posts to output the correct amount of voltage to the battery. In my set-up, the early A bodies utilized 2 wires on the factory alternators, one for BATT, the other for FLD. I ended up reusing the FLD line and hooked that up to my green wire at the voltage regulator, and then tied my blue wire into the ignition - right at the wire were the factory ballast resistor would get its power, and also tied the other FLD post to that same connection. Charging around 14.67V!

NOTE! Do not buy Chinese voltage regulators, they may look good for the price, but they do not last, only last a week. Be sure to buy a USA made/Mopar voltage regulator, and you won't keep kicking yourself. Also, be sure to have a voltage gauge meter hooked up to monitor your voltages. Literally my voltage would spike up to 17-18 volts with the chinese cheap crap voltage regulators. Now it always stays where it should with one made here in the USA!!!
 

rumblefish360

I have escaped the evil Empire State!
FABO Gold Member
Joined
Jun 21, 2005
Messages
45,856
Reaction score
18,703
Location
Florida
On my '00, 5.9 swap into my '71 Duster, I just spliced the wires and have no issues.
 

Infecteddog

Well-Known Member
Joined
Feb 14, 2015
Messages
364
Reaction score
15
Location
NC
On my '00, 5.9 swap into my '71 Duster, I just spliced the wires and have no issues.
Some years have a VR in the computer, others don't I recall '98 as a transition year but I forget if they added the external or got rid of it. I know I've heard of that terminal in the PCM burning up and an external VR swap fixing the charging problems.
 

rumblefish360

I have escaped the evil Empire State!
FABO Gold Member
Joined
Jun 21, 2005
Messages
45,856
Reaction score
18,703
Location
Florida
Revisiting.....

I first have to state, I made 2 mistakes and the first one I don't think is a issue but the car is a '79 Magnum, but here is the issue. I'm having issues charging. I first stated no issues. And that was true since I had just done it and all seemed fine. But that has not been the case after a while.

The above video & wiring diagrams, is it for with use with the computer? Or no computer?
 

rumblefish360

I have escaped the evil Empire State!
FABO Gold Member
Joined
Jun 21, 2005
Messages
45,856
Reaction score
18,703
Location
Florida
OK thanks. I'll have to get on the car soon since the weather is getting sweet again. Not charging with the '00 Alt. Won't let me get far! LMAO!
 

rumblefish360

I have escaped the evil Empire State!
FABO Gold Member
Joined
Jun 21, 2005
Messages
45,856
Reaction score
18,703
Location
Florida
Oh hey brother! I'll need a few days to reply properly. I need to recheck everything to be sure. It has been a while.
Trying to handle a few other irons at the moment that REQUIRE my attention before I get to the fun stuff.

I'll be back shortly..... I hope..... LMAO!
 

rumblefish360

I have escaped the evil Empire State!
FABO Gold Member
Joined
Jun 21, 2005
Messages
45,856
Reaction score
18,703
Location
Florida
Not charging at battery voltage or?
OK, now that I am finaly home and had some time (LMAO!) the last guy to touch my car (Tansmission work) must have knocked the wires and separated them at the Alt. connection. The OE '00 Alt. is now charging as intended in the '79 Dodge with the OE wiring.

Thanks Infecteddog.
 
Top