Magnum Alternator Wiring

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JimmyV

JimmyV

MOPAR!!
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This has probably been covered, i have tried searching but not quite getting the info i need. swapping to a magnum from an LA as far as the charging system is concerned can i just hook the existing regulator wires up to the magnum alternator? and if so which one goes where? i know you can buy a kit. but what if you already have a working regulator all wired up. any input or help pointing me in the right direction to where i can find the info would be great thanks!
 
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Just reuse your two existing factory wires. It’s that easy. Doesn’t seem to matter which wires get hooked up on which stud.
 
^^THIS^^

There are only two "small" terminals, they are interchangeable. One to your Mopar blue wire (field voltage) the other to green (to regulator)
 
Just make sure the regulator is grounded well. The magnum alternator has a lot more amps than the factory LA one did. Also check the ammeter connections at the dash.... ask me how I know this!!!:BangHead:
 
Did you actually ask a question about your car without describing it? 67Dart273 usually jumps on such miscreants w/ "1932 Fordson tractor?".
The answers assume you have a 1971+ w/ the Vreg shown. Doesn't matter which field wire is which. If you have the earlier Vreg w/ 1 field wire, just ground the other field terminal on the alternator.
 
You may want to consider bypassing the amp meter. Very problematic. They burn up and can catch fire.
 
Would using a lower AMP alternator (90amp) be a safer option to use? with the stock wiring system?
The alternator on my 01 5.9 is putting out around 136-160 amps and it smoked my fusible link.
 
I would not use more than 45-50A at most on a stock harness, bear in mind these are old and could be already damaged. In no particular order, every wire end, the wire size itself, most especially the bulkhead connector terminals, and the ammeter and it's connections

If you cannot do anything else, just get a fuse link/ breaker/ fuse and put a nice big no8 or larger wire from the battery to the alternator. You DO want to fuse this.
 
I use the stock Magnum Alt. However, I did unplug all of the bulk head connectors and cleaned both the main terminal and the connectors. And, checked each and every wire. Years (40+) on the wiring harness will show its age. If you have any brittle wires anywhere then they will be the ones to go up in flames.
You may consider a complete harness if there are many questionable wires. As stated above use fusible links.
 
The amperage capability of the alternator is not the only consideration.
If you properly connect the alternator and have a suitable size output cable between the alternator and battery positive post, you can still end up with another meltdown due to existing car issues, like the amp meter in the dash.
Bypass the amp meter as others have suggested, and make sure whatever alternator you run has a clean ground path back to battery negative post, and make sure the alternator output wire is upgraded.
 
I would do the MAD electrical ammeter bypass. Did it on my sons '71 Charger (noticeable difference w/ stock alternator) and will do it on my new-to-me Valiant as I put it back together.

Catalog
 
Clicking on the "catalog" link will take you to the page. Not sure why it came up that way.
 
Hi, im having too high voltage when I get over 2000rpm. At idle it charges 14.3 and when I put up to 2000 it charges 17 to 18 volts. Regulator is bolted to the fender and I made an extra ground wire also. Regulator is new from rock auto, could it be broken otb?
 
Dusterfreak said:
Hi, im having too high voltage when I get over 2000rpm. At idle it charges 14.3 and when I put up to 2000 it charges 17 to 18 volts. Regulator is bolted to the fender and I made an extra ground wire also. Regulator is new from rock auto, could it be broken otb?
Click to expand...


Check and make sure ALL of your connections are good, tight, and CLEAN. No rust, corrosion, paint, etc. The ground is usually the problem but any of the connections can cause issues.

The regulator could very well be bad even though it's new. That is becoming so common its ridiculous.
 
Start by pulling loose the field wires and check them for continuity to the case (ground) They must be open to ground. Double check the VR connections and ground, and if that is OK replace the VR
 
Send the regulator back and get a HD one from the alternator man online. Make sure it’s grounded good and the battery grounded. Have the alternator checked. I had everyone of these issues when working on mine and my friends charging systems. Overcharging for long will kill the battery, ask he how I know!!!
 
Reviving this old thread since I am doing something similar.

I am adding a 5.2 magnum to my 69 Dart.

I had previously upgraded to a powermaster 95 amp and I checked my wiring harness under the dash and at bulkhead and everythign checks out fine. I also checked the Ammeter connections and they look good as well. I got lucky getting a nice non hacked up car. The gauge works as well. I did upgrade the voltage regulator to the nice Mopar performance one and had no issues regulating.

The new alternator is a 136 amp unit. Should I just not use the Battery + wire on the stock harness and just use an 8 ga wire directly to the + side of the Battery?

I don't want to burn the Fusible link, but would have been nice to keep the ammeter hooked up as well.
 
The fusible link is not the main concern, rather usually the plastic housing of the bulkhead connector melts. A little too much resistance (corrosion) plus upgraded alternator, generates heat (i^2 * R). Double the current and 4x the heat. Those wires may remain connected, but may begin touching other wires they shouldn't as the plastic melts. Too much current and resistance can also melt the ammeter connections and perhaps even damage the ammeter. There is a solution to keep your ammeter alive, yet protect it. Search for my post "Modernized Wiring" with my name (from google) to find a way with parallel diodes. Not for people who don't understand basic electricity. One gomer thought arguing with an engineer (me) there was smart. Another place to address corrosion is the welded "ALT" connection under-dash. Unwrap the fabric tape and you may find a green mess.
 
BillGrissom said:
The fusible link is not the main concern, rather usually the plastic housing of the bulkhead connector melts. A little too much resistance (corrosion) plus upgraded alternator, generates heat (i^2 * R). Double the current and 4x the heat. Those wires may remain connected, but may begin touching other wires they shouldn't as the plastic melts. Too much current and resistance can also melt the ammeter connections and perhaps even damage the ammeter. There is a solution to keep your ammeter alive, yet protect it. Search for my post "Modernized Wiring" with my name (from google) to find a way with parallel diodes. Not for people who don't understand basic electricity. One gomer thought arguing with an engineer (me) there was smart. Another place to address corrosion is the welded "ALT" connection under-dash. Unwrap the fabric tape and you may find a green mess.
Click to expand...


Ah makes sense, Thanks! I will look into it.

I have some basic understanding and IPC training/ certification so I can get by. I can definately learn more from an engineer.

Thanks again!
 
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