About alternator upgrades ( and wiring )... my experience today.

[Nacho-RT74]

Just to let you know. I have had as many of you guys charging problems at idle and also when I have lot of electrical devices working. I also have halogen beams.

Even I always have known about the way to save the problem never did it since my stock alt was working decent, but last week I have had a lot of problems. so I decided went to an original Mopar stock and NOS laters 70s alternator.. dirty cheap here by the way, since nobody want them because people think doesn't works and everybody change to GM charging system. Is true that replacement parts are becoming hard to find here for same reason.

I got:

-trully and incredible perfect charge at idle.
-in just 15 minutes a fully charger batt... was around 1/3 of power reserve.
-Ammeter needle fixed when press gas pedal, turn on lights, press brake pedal, turn on A/C blower etc...
-Brighter cluster, parking lights etc... also beams.
-Faster blinker fuction since bulbs are getting more juice to get heat on flasher, making it quicker cut and go power function.
-Perfect and constant wipers speed.
-Everytime I started the engine, in just 1 minute or less, ammeter needle was in middle after get back on batt the power used on starter function.
-No heat on ammeter since charge is equilibrated, and never gets overcharge current there.

What I have on my car to get that response and keep safe from the extra load:

-Parallel wires trought firewall with a grommet to the original charging wiring on engine harness trought bulkhead connector from alt stud up to ammeter and from there up to starter relay... wasn't ONLY my idea... after I decided went with that long time ago, I discovered that Original wiring diagrams on 71 had that extra wiring option to more than 65 amps alternators ( specially with town package to the extra lighting ).
-small pulley. Don't remember the diameter but I think it is around 2" and a quarter.
-My car had already the electronic regulator and wiring.

Fits the same from the old round back alt to the square back alt.

So if I can give you an advice... run up the closer junkyard, search on any laters 70s alternator, that YOU know that will find on maybe $10 or less, and upgrade.

I disasembly my old one and compare with this one and as I did know only difference was really the wider stator. Almost 2 milimeters wider coil... one milimeter by side.

So I still have a complete Mopar with just stock parts.

[monty76]

Did you have the eletric upgrade from the old website that bypassed the amp meter? If so are you saying you "undid" that and ran 2 parallel wires instead?

[monty76]

One more question, how far in to the 70's to get that alt, 73,75,77 ect?

[Nacho-RT74]

I just added the extra wires and keep the original wiring and gauges. I'm not agree with the "madeletrical" website solution. They say there that all the current ( electrical load ) will flow outside the passenger cab since with that they say the main splice is on starter relay stud and that is not true, since the main splice is still INSIDE the cab on black wire where is connected the accesories wire, lighting wire, ammeter and specially ignition wire. Only way that yo have the main splice and big current flow outside the cab is that you connects EVERYTHING directly from batt or starter stud and this is not the case. If this was the case you must have 4 WIRES at least running up to starter relay stud or batt.

Ammeter is a good gauge to keep it working, even is true that add a voltmeter won't hurt anything. I didn't bypassed stock ammeter gauge.

Only true that they say are the original stock spade terminals on bulkhead are awesome week and wont support the extra load, but to save that, isntead cut and run directly throught bulkhead is just enough run parallel wires trought firewall keeping the original wiring. As stated, after I thought to do that, I discovered that MaMopar ALREADY HAD THAT OPTION with more than 60 amps alternators, since 71.

About alternator itself. Buddy, there is not more that 3 kinds of alternators as far I know. the round back kind with one field ( pre 70 ), the square back back double field ( post 70 ) and the double field squareback with center iron stator inside the alt case, not visible from exterior. I think this one was available since 75 or so.

Any of this one later mentioned with center iron coil stator hidden by case will work.

BTW I'm still working on send everything, sorry the delay

[Nacho-RT74]

here diagrams.

First one: original.
Second one: same but made by me.

[Nacho-RT74]

madelectrical option:

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

Even is true that works and I'm a purist, you don't need to drill bulkhead, cut, etc..the original wiring to make it work better ( except if you already have burned areas ). if already MaMopar had the solution.

1- as you notice, main splice is still inside the cab, only that you are saving is that you are doubling the wiring up to splice from both sides bypassing and joining the ammeters ones. Is true that load is running by two wires ( both side of original wiring used on ammeter ) instead one, but you still have ONE fusible link ( so only one wire ) from starter stud to inside the cab. True is a fussible link and will blow when you have some trouble. MaMopar wiring will do the same when you have same trouble and will support the extra load with higher amp output alternators.

2-when car needs electrical power will run from where comes, no matter batt or alt. Then is not true that extra load won't be inside the cab and run to batt... GOD !!! IF BATT DOESN'T HAVE JUICE to feed the car, THEN ALT WILL FEED to anywhere, BATT WON'T BE FEEDED FIRST to get complete charge. power runs to where is needed FIRST, THEN devices will be feeded because they are the ones are working and suking juice. Of course Batt is also feeded with the extra load that car isn't needing untill gets full, but is a parallel process. Alt power is shared. So if devices needs power, will run up to main splice INSIDE THE CAB anyway.

3-I don't like a gauge as ornament on cluster. Ammeter works and works good.

4-Batt is getting full charge anyway passing by ammeter with extra Mopar wiring, you still are feeding the batt when batt needs charge. Only difference on madelectrical and original extra wires is around 2 feets longer wire and ammeter on the way. Then you still will have a real time reading about what is happening on your car.

Only real true that they save is cut the weak spade terminals at bulkhead... rest are half true. You don't need to cut if run parallel wires.


After this "upgrades" you only need to keep your eyes on steering column harness up to ignition switch, specially the red one.

[2Gunz]

This looks like a decent upgrade if you must keep the amp meter. Which.... really should be replaced.

The largest problem with it is you still rely on the weakest part of the system to charge the battery.  The amp gauge.

[monty76]

Hey Nacho, on the square back alt. are you running a 65amp?

[71_deputy]

hey Nacho- good info for the guys!!!!  done this exactly to the Deputy when I restored her!!!  spent at least 60 hours in changing/upgrading the wiring so that I never had to deal with all Ma mopars issues agian!!!!!!!!!

[Nacho-RT74]

I'm pretty sure running more than 65... I think is 80/90 amperes one.

[monty76]

Ok, I checked at the parts store. It's either a 65a or 100a alt. I'm guessing a 65a alt with the square back will be ok?

[Nacho-RT74]

If you make an upgrade go for the best posible if money is not a problem and there is not to much difference on prices.

I would go for 100 amperes even if your car never will need that ammount of power. You will have a lot of headroom on power.

[monty76]

Was talking to a mopr dude at an auto electic shop. Told him I get a voltage drop at idle. He said that was the norm for mopar. He mentioned that there was kit at one time allowing you to install an AC Dleco alt. Mopar alt has the mounting bolt at 1 and 9 where as the AC Delco has them at 1 and 7. Anybody ever heard of this?