Upgrading the Alternator, anything I need to know?

[72RoadrunnerGTX]

Other that the stud connections to the internal shunt bus bar, there is no other potential source of heat within the factory ammeter. With tight connections and good insulators there will be no external or “internal” failures while operating in the current range as designed, the notion that ammeters will spontaneously fail internally has no basis in fact. Heat is generated when connections fail period, when resistance builds and/or a failed/crushed insulator allows stud contact between the stud and cluster frame.

No argument here that the Chrysler designed charging circuits have weaknesses, they were never designed to last more than a few years, after the warranty period lapses and it’s time for trade-in. All automobile manufactures have used ammeters since the inception of automobiles. Fact is they provide a more complete and accurate information, in real time, about the current state of the battery charge-discharge and operational health of the charging system, much more info than a volt meter or a no-charge idiot light.

Automotive manufactures moved away due to cost not because of some inherited safety concerns with the use of an ammeter. That said, Chrysler/Dodge waited way too long into the age of plastic dash construction in the case of late seventies trucks.

My preference/opinion? Rebuild the original harnesses, replacing original 12-gauge charge circuit wires with 8 gauges or larger, by-pass the bulkhead connectors, run straight through to the ammeter. Protect the wires passing through the firewall with appropriate sized grommet. Use an appropriately sized fusible link based on vehicle loads at the battery or starter relay. Tight connections, not too tight that the fiber insulators are crushed. All vehicle loads on the alternator side on the ammeter, no additional loads of any kind on the battery side.

Strange, as I read these posts, the condescending tone I pick-up is not in any of Nacho’s posts.

 

[Billccm]

After a long period of sitting, my car takes a fairly long, multiple extended crank to start. I charge the battery before that long extended crank, but I would watch my under dash ammeter swing to 20-22 AMPS for about a minute, or so. One day I decided to measure the voltage drop from the alternator to the battery during that >20A period. The voltage drop was 1.3V.

My point of view is voltage drops are bad, even if just for 1 minute, or so. Thinking out loud, (P=E*I), 1.3Vdrop*20A=26 Watts of heat being dissipated somewhere. Maybe bulkhead, ammeter, inadequate wire gauge who knows? I followed the MAD bypass, replaced the under dash ammeter with a voltmeter, and on the next start after a long settle period the voltage drop was 0.18V. So, 0.18Vdrop*20A=3.6 Watts. I reduced the heat dissipated 86% which I'm sure you will agree is a good thing to do, and a definite improvement.

I agree that with new bulkhead connections, harnesses, and ammeter you are good for many years of driving. I also agree that the ammeter design and bulkhead path is not efficient and it is a definite improvement to bypass and convert to a voltmeter.

 

[72RoadrunnerGTX]

Sounds to me like you had voltage drops relating to various Packard connections. 50-yearold Packard connectors in the changing circuit through bulkhead connector and undersized wiring are the primary culprit. There won’t be measurable voltage drop through an original ammeter in good shape.

 

[Nacho-RT74]

Strange, as I read these posts, the condescending tone I pick-up is not in any of Nacho’s posts.

Sometimes I become hardcore on this because the way how ppl says I'm wrong or kinda stupid somehow, like I have not experienced this personally and made all kind of changes and mods ( yes including the voltimeter add and ammeter bypass in the past ). Specially when I made all the diagrams showing and explaining how it works step by step and nobody can tell I'm wrong on how to read the amm and how to save the load going through with a bigger alt.

then if ppl choose one or the other way, that's at each own, but keep telling me I'm wrong on this... no way!

I simply have found how ppl doesn't know how to read the amm and thinks a charge reading is good sign of the alt working where is not. That is bad!!! centered needle is the best charge status. It means batt is not being sucked and alt is enough to feed the car demands.

Next... the ammeter is actually a Batt gauge and not an alt gauge NO MATTER what the factory said when labeled it as ALTERNATOR. An alt doesn't discharge or charge since is not a reservoir able to hold load. The batt is... there is not a way to get an alt able to get discharged and if you think is, please explain to me ;)

Charge reading means load is going from alt to batt due a discharged batt or accesories ( i.e. headlights relays, cooling fans ) attached to batt, which is wrong. Then ppl wonders why the overload on the charging system and why everything burns out on a system wasn't designed to work like that, PLUS the mistake made by MaMopar on the low capacity alts at low speeds.

Next big mistake: Huge load capacity batts on stock low capacity alts... takes forever to get it charged back, adding stress on a system it wasn't designed for that. It must be made the other way around, or change both at the same time.

as mentioned, there are many ways to make things, but say I'm still wrong.... naaaahhh ;)

( After all, I'm posting the info I have experienced since the main question was ANYTHING I NEED TO KNOW LOL )

 

[Dubjitsu]

Thanks everyone for the input! I'm going to read through the links to the literature provided, likely bypass the ammeter (I have a voltmeter hooked up now anyway), pick up a headlight relay kit and try some of these things listed here to see how it reacts. I'm also considering adding a keyless power door/trunk lock system, so obviously this will play into the electrical equation if I do go that route.