Who's using the newer high output ALT. available today?

[b5blue]

Years back I swapped to 120AMP Denso and it's sooo much better. However now I'm pushing the 60AMP idle output with my A/C on high and everything else running like at night in the rain so wanting higher output @ idle. I'm looking at this:
https://www.qualitypowerauto.com/pages/ChryslerMegaAmp.php    Anyone using one of these?   

[John_Kunkel]

I'm running one of their Mega-Amp 150 with a single belt. My only complaint is the pulley, the groove is too shallow and doesn't make full contact with the belt so the belt slips under high demand (like right after startup) so I replaced the pulley with a larger one with a deeper groove. Never drops below 13.5 volts at idle with everything running.

With a two-belt installation slippage probably won't be a problem.

[b5blue]

Thanks for the insight John. 

[LaOtto70Charger]

What did you change in your electrics to run those alternators? Now that my ac is recharged I need to start looking into it.

[John_Kunkel]

No need to change the electrics with the Mega-Amp units, they offer single (pre-'70) or dual ('70-later) field options.

https://www.qualitypowerauto.com/item_557/Chrysler-Mount-Mega-Amp-Alternator.htm

[LaOtto70Charger]

OOOO  I like that. 

[303 Mopar]

No need to change the electrics with the Mega-Amp units, they offer single (pre-'70) or dual ('70-later) field options.

https://www.qualitypowerauto.com/item_557/Chrysler-Mount-Mega-Amp-Alternator.htm

This is the one I have on the 505 stroker in my '68.  I run stereo, amp and Sniper EFI with no issues at all.

[Marcath1965]

I installed the 150 Mega Amp in my 69 Charger with two pulley set up. Added a 4ga wire to the battery and it runs fine with 15 volts going into the battery. The battery is a 78 style. I am seeing the an issue with the amp gauge now and it is running on the negative side and goes even more negative when the lights are turned on. Any ideas as to what would cause this?

[John_Kunkel]

Welcome to the board.

Running the 4 ga. wire to the battery (good idea) effectively takes the ammeter out of the charge circuit, it's still there but most of the current flow bypasses it. Just change the ammeter over to a volt meter or add a voltmeter to monitor the charging system.

[Marcath1965]

Thanks, any way to have the amp meter still work correctly and not have to worry about installing a voltmeter? I'm an OCD purist, a real pain sometimes, when it comes to what trying to keep things looking and acting, like they did when they came from the factory. It's a curse!

[Kern Dog]

No need to change the electrics with the Mega-Amp units, they offer single (pre-'70) or dual ('70-later) field options.

https://www.qualitypowerauto.com/item_557/Chrysler-Mount-Mega-Amp-Alternator.htm

Thank you for providing help on this. I am confused a bit though.
Not disputing your words, I just wonder why others have warned against using high amp alternators. Their claims have often been that the stock wiring cannot handle the increased output. I may be wrong but I think that Nacho74  is one of the people that mentioned it.

[Pete in NH]

Hi,

The original alternator circuit wiring is 12 gauge wire that was marginal with the stock 35 to 45 amp alternators. The Packard 56 pins in the bulk head connector are also marginal at 35 amps. So, with big newer alternators you really want to get rid of the stock ammeter and its original wiring and go to a voltmeter. You also want to run the alternator output directly to the positive battery post through an appropriate fuse. You then want to run a 8 gauge wire through a 50 amp or so fuse to the wire that went to the old ammeter negative side to power the car's electrical needs.

[c00nhunterjoe]

I ran a seperate set of circuits to a new fuse box to power my upgraded electronics.

[Marcath1965]

Great advice and many thanks. The circuit breakers definitely make sense. Anyone have any ideas if there is a voltmeter that will fit in he dash and look like it belongs there?

[b5blue]

Thanks, any way to have the amp meter still work correctly and not have to worry about installing a voltmeter? I'm an OCD purist, a real pain sometimes, when it comes to what trying to keep things looking and acting, like they did when they came from the factory. It's a curse!

Remember the gauge is labeled "ALT" and meant to show if current is being drawn from the battery, if so how much or is there an over demand from ALT output. So a danger really only exists for high output ALT being run while the battery is in an unacceptable state of discharge. Normal operation your only ever restoring the amount of discharge from starting, why the FSM uses the term "Starting Battery" when referring to the battery. (Only meant for starting, nothing else.)
  For me this all started many years ago when I complained to friends who own battery and starter/alternator shops about low idle ALT output. We collectively insured I had the best battery/alt./wiring and I just did my best to load manage as the car was driven daily. Now that I find myself wanting to run my newly added A/C on high (and loving it!) when the feels like is 110 I can tell with wipers and lights on @ idle I'm reaching the Denso's idle output max when the extra pusher fan I added kicks on.
  So as long as you NEVER try to charge a badly discharged battery and have added fused distribution to a fleet upgrade your ALT gauge will never see damage if when it reads to ether extreme you shut the car down to fix a problem. So many times I see this argument about the gauge yet who will keep driving with zero oil pressure or the temp gauge pegged?     

[John_Kunkel]

Not disputing your words, I just wonder why others have warned against using high amp alternators. Their claims have often been that the stock wiring cannot handle the increased output. I may be wrong but I think that Nacho74  is one of the people that mentioned it.

Yes, it's wise to upgrade the wiring but I don't agree on the method some recommend. In my case, I simply add a #4 or 6 wire directly from the alternator to the battery. Of course, this parallels the ammeter and nullifies the ammeter reading so a volt meter is needed to monitor the charging system.

The main purpose of a high output alternator isn't the max amperage output number but the higher output at low speed. In most cases the high output unit will never be called upon to produce its max.

[b5blue]

Between fusible links and 8ga. fleet upgrade fused at 60 amp my system is designed protected even in a crash. (My OER gauge is rated at 60amp capacity.)

[Marcath1965]

ZOWIE, all this good info. I replaced my 45 Amp with a 60 amp and then to a 150 Mega Amp. With the 45 and 60 Alt the amp meter was showing as it should. When I installed the 150 amp alt. I saw a -4 showing all the time, with lights, radio with 50 watt speaker amplifier, and directionals I am showing a complete swing to the discharge on the amp meter. I could have the same on with the 45 and 60 amp alternators and it would show a slight, needles worth of charging on the positive side. I have hooked up a voltmeter on the new alternator at the battery and as I said earlier, it just shows it is getting about 14-15 volts going into the battery. So why the extreme discharge on the amp meter? Johns explanation sounds like it makes sense to me as does b5blue. The folks at Quality Power told me it would be transparent if I just put a 6 gauge from the alt. to the battery, I used a 4g, It seems it's not. I hate hanging gauges off the dash or anything else that didn't come with the car so would love to continue to use the amp meter if at all possible. Sounds like it's not.

Thanks for all the great input.

[b5blue]

It is an alternator gauge so think about that. 

[Marcath1965]

Not to be flippant but if I knew the answer, I wouldn't ask. I'm not an electrical type, I turn wrenches.   

[b5blue]

Check for discharged battery. 

[Pete in NH]

Hi Marcath1965,

If you only added the 4 gauge wire between the alternator and battery, the battery charging current is flowing through that new wire. If you left the original fuseable link and original wiring to the ammeter in place it is now only indicating the electrical current required by the electrical equipment in the car. It will show this as a steady discharge reading.

The folks at Quality Power didn't give you the right information, adding that new wire will defeat the ammeter in showing battery charging current. That you measure 14 to 15 volts at the battery indicates the system is working as one would expect.

Hope this explanation helps.

[b5blue]

Ah Pete thanks! I was not thinking he ran a direct to battery wire. 

[Marcath1965]

Yes Pete, it did help. Thank You. As I mentioned in an earlier question, since I cannot use the amp meter any longer, could you,

1.  Recommend a gauge that will fit in the place of the OEM gauge in the dash and look like it belongs there? 
OR
2.  Confirm it is not detrimental to leave the original amp meter in the dash even though it reads negative all the time? You indicated I should use a 8 gauge wire with a "50 amp or so," fuse to the amp meter in the dash, that would presuppose that the voltmeter is a separate meter and the amp meter remained installed.
3.  Is it "just" the the wire to the negative side of the amp meter that needs to be changed, or should I change others?

Final question, for now anyway, Is this something you do for a living or just for fun. I ask because I am in Maine, born and raised in Concord, NH and would be glad to take a trip over if you do this for a business. I have a ton into this car and I don't want to see it burn up because I did something half a - - - d.

Thanks for the help,

MarCath

[Kern Dog]

In 2013, I moved the battery to the trunk and added a FORD solenoid. I have a ground cable running from the engine block to the battery and a ground from the engine to the core support.
The positive from the battery goes to the FORD solenoid. It is always live. The other terminal is the start of the main positive cable that runs through the car and to the starter itself. The main cable is only live when the starter is cranking. I have a #4 wire from the starter relay back to the FORD solenoid to trigger the starter.
I do wonder if I should run a charge wire from the alternator stud to the battery directly.