Alternator upgrade suggestions advice

[real0803]

I have a 76 Doba that has a stock alternator . I believe the amperage is 60amp . I do notice at idle it drops in the 11's when the lights are on , it then jumps to around 14v when driving. The dash lights are super dim. Now do you think an upgraded alternator will fix that problem? If so how many amps should I jump to ? 110 or 200? I plan in the future to put a simple stereo system with a sub. I was looking on Summit , does anyone out there recommended a brand ? I was thinking about Powermaser , Tuff Stuff or even then Proform one I came across . I would like a direct bolt on but if there is advantages of something better, I'm open to all you're opinions .

 

[RJRENTON]

I have a 76 Doba that has a stock alternator . I believe the amperage is 60amp . I do notice at idle it drops in the 11's when the lights are on , it then jumps to around 14v when driving. The dash lights are super dim. Now do you think an upgraded alternator will fix that problem? If so how many amps should I jump to ? 110 or 200? I plan in the future to put a simple stereo system with a sub. I was looking on Summit , does anyone out there recommended a brand ? I was thinking about Powermaser , Tuff Stuff or even then Proform one I came across . I would like a direct bolt on but if there is advantages of something better, I'm open to all you're opinions .

View attachment 1636696

Light dimming at higher electrical loads, and lower RPMS with a corresponding voltage drop (11s volts +/-) and resuming normalcy when speeding up IS A TOTALLY NORMAL OCCURANCE. YOU DO NOT NEED A NEWER (higher amperage output alternator)......just drive and enjoy your car as is......now you'll hear dozen or so "experts" and their reasons why the world will come to an end IF you do not change to a Powermaster alternator and rewire the vehicle........it's not broke and doesn't need fixing.......just my opinion of course....
BOB RENTON

 

[radical rob]

Lights dimming at idle etc means alt at that rpm is not producing quite enough juice. Since you want to add some upgrades, upping the alternator will be needed. Any you mentioned would be good choices, I personally use a power master on my rr.

 

[hunt2elk]

Like stated above, that is normal, and the way these old rigs operate. Lights are dim at idle because this style of charging system doesn't do much if anything at idle.
Depends on what you are looking at doing. I switched my alt to a Denso style with an internal regulator. That system puts out 14 volts even at idle. The dimming headlights can be upgraded by putting in a relay kit. A member on this site sells a really nice kit for that.

 

[real0803]

Like stated above, that is normal, and the way these old rigs operate. Lights are dim at idle because this style of charging system doesn't do much if anything at idle.
Depends on what you are looking at doing. I switched my alt to a Denso style with an internal regulator. That system puts out 14 volts even at idle. The dimming headlights can be upgraded by putting in a relay kit. A member on this site sells a really nice kit for that.

The dimming on the dash is at idle and driving as well. Maybe the lightbulbs need replacing ? Do you have the link to the seller ?

 

[hunt2elk]

@Crackedback sells the headlight relay kits.

 

[bobsgtx]

You should do some testing before just replacing parts. You need to do voltage checks with engine idling and headlights on to make sure you don't have some wiring/connector issues.

 

[hunt2elk]

The dimming on the dash is at idle and driving as well. Maybe the lightbulbs need replacing ? Do you have the link to the seller ?

You have something else going on if the lights are dimming while driving.

 

[real0803]

Well the dash light stay dim but headlight are good

 

[Nacho-RT74]

Normal doesn’t mean desireable. Even less on actual driving conditions &/or cities. Into the country could be diff because a car iddling could be not the regular stage like at constant traffic light stops and transit.

It is/was also normal get burnt the bulkhead, specially at alt path (not so much at batt path)… this is/was due the constant batt load request to be recharged, claiming more load and for LONG time than the car needs itself after a low alt output stage running throught the system unable to handle it. So just because is normal must we still keep accepting that destiny?

Normal is also that dusty/rusty contacts due environment conditions on engine bay and abuses along the car life increases resistance to the system, making it even worst.

Yes, upgrade the alt, upgrade the alt path up to the amm and live happier with it.

The best solution is get an alt able to keep the car load demand at the minimum speed as posible. Something able to give AT LEAST, 45-50 amps iddling, if you ask me, but more, better.

The more the time amm registers ZERO reading (and this means an alt able to provide all the load request as posible ) the healthier will be the charging network.

It could be helped also with the smaller alt pulley at posible to make it spin faster. On late 70s (or it was already at 80s?) this change was made from factory.

And NOTHING must be sourced from batt side on amm cars equipped. This increases some of the bulkhead burning issues, aside a wrong ammeter reading.

I HAVE MADE IT (my Charger has being a REAL daily driver car on a 7 millions ppl city) … AND I’M HAPPIER.

I still don’t know somebody who has upgraded the alt (with a good one) and is not happier than before. But please, accomplished with some wiring upgrade and mantenience on the system.

 

[Nacho-RT74]

Being a 76, it must get a Shunted ammeter/charging system, so the batt charge/discharge load is not going anymore through the bulkhead, but still the upgrade will keep everything healthier.

Check the power path up to the cab thought.

 

[bc3j]

This is how I solved my dim headlights at idle. I recently installed an alternator from a 1985 Diplomat (60amp). I read Mopar made changes to the alternator in 1985 using a thinner stator between the case end shields as compared to the thicker stator in previous units. I used LEDs in every light that is on when the headlight switch is on. Headlights are H4 lo/high beam and H1 high beam (from Daniel Stern lighting) with Crackedback’s harness. At idle I have between 14.4 and 14.7 volts using a factory Mopar alternator. My ammeter is in use with a bulkhead wiring bypass. The ammeter is neutral when the lights are on. The ammeter moves to charge about a needle width then almost immediately returns to neutral when I turn on the lights. I have no dim headlights at idle. Very happy at night with this setup. The H4s are impressive.

 

[Nacho-RT74]

That’s what I say when I still don’t know ANYBODY regretting that alt upgrade. But a correction:
Thinner stator no, wider in fact. Just the previous visible area is not anymore visible down the redesigned case.

The windings are wider, not so much the iron nucleus. Case is wider in both senses (diameter and deepness) to be able to accept and hide the new stator assembly. In some assemblies installing these alternators requires a larger belt and a small trimming job on the rear spacer to be able to fit the new one due the new size. (That was my case, BB 74)

However to proceed with this upgrade using a stock replacement, I would use a 78-80 amps unit, not a 60 amps unit. For the same price those 20 amps extra (which means maybe 7-9 amps more at iddle ) worths the price.

 

[kiwigtx]

Now I'm almost afraid to say I use a Powermaster alternator - 75 Amp output running with a peak at 90 Amps. I am using that because the OE 37 Amp alternator wasn't cutting the mustard with headlights and a couple of add-ons such as A/C and stereo amplifier. I totally rewired my A100 as per the FSM wiring diagram - the only deviations are that I used insulated studs instead of the 'fuse-welded splice joints' that the factory used.....I don't have a facility to do that.

I also added more modern replaceable fuse links instead of the fragile glass tube fuses in the regular fuse box. I am nt looking for a Concours show to enter, but I do want safety, so I made a few compromises.

I have noticed while driving that my ammeter is showing a reasonably steady rate of charge - hard to quantify, but it's in the 20-30 Amp range. The longer I drive the less it is.....so I suspect everything is working correctly. Also I can now leave the battery switched on for several weeks at a time without going flat.

 

[Nacho-RT74]

Mmm if everything is correctly sourced (alt side) the only moment you should get a steady charge reading is after a long time discharge period, like after the cranking moment. The longer the discharge stage or rate was, the longer will be the opposite. Althought the starter motor load is not registered by the amm.

On my car with 80 amps alt after a regular cranking time, the charge rate on 15-20 amps but slowly decreasing just last long for around 3-5 minutes untill reach 0

Otherwise the ammeter should show a centered/zero reading or really close to that with that alternator under normal circumstances (and a healthy batt)

 

[72RoadrunnerGTX]

I have noticed while driving that my ammeter is showing a reasonably steady rate of charge - hard to quantify, but it's in the 20-30 Amp range. The longer I drive the less it is.....so I suspect everything is working correctly. Also I can now leave the battery switched on for several weeks at a time without going flat.

That would indicate you have some incorrect loading at the battery or on the battery side of the ammeter. As mentioned, a fully charged healthy battery will draw verry little current on its own, ammeter should be centered under normal operating conditions.

 

[kiwigtx]

That would indicate you have some incorrect loading at the battery or on the battery side of the ammeter. As mentioned, a fully charged healthy battery will draw verry little current on its own, ammeter should be centered under normal operating conditions.

I run my A/C on full speed cold when driving all the time. Sniper probably consumes some power along with the electric fuel pump.

 

[Pool Fixer]

I’d check the wiring first. Clean everything and do the ammeter bypass. Focus on the firewall bulkhead connector. While you are at it, put the headlights on a relay

I don’t recommend upgrading to the higher amp alts for the power. I always recommend because the higher amp MODERN alternators charge better at idle.

Stock denso 130 amp alternator from
An ‘02 ram van, one ton bolts right in and it’s even externally regulated like the stock alternator.

Mine charges 14.2 at idle headlights on, efi computer on, efi fuel pump running, dual 1250 SPAL fans running

 

[72RoadrunnerGTX]

I run my A/C on full speed cold when driving all the time. Sniper probably consumes some power along with the electric fuel pump.

If the Sniper and the fuel pump are connected straight to the battery as their generic instructions specify, that would explain the constant false charging indication on an ammeter-based charging system. May as well do the ammeter by-pass then, as the original purpose of the ammeter will be defeated by the misplaced loading. If you want the ammeter to work as it was designed, connect those added loads to the alternator side of the ammeter as are all factory loads. Load placement matters.