Ammeter Bypass

[Steve340]

I did try to find the source/article I read but no luck finding it - so I thought I should ask here.
I did the ammeter bypass under the hood with a large wire from the alternator direct to the starter relay terminal.
I left all the original wires/ammeter connected. I installed a 12V LED indicator inside the car so I can tell if it is charging as the ammeter stopped working.
Is this correct or is there a better way?

 

[moparleo]

Here you go:
Catalog
Catalog

 

[Challenger RTA]

Just going over this with 72RooadRunnerGTX maybe take a look at his video. Factory original Chrysler ammeter-based Charging System and additional loading. Load placement matters!
Maybe show us what you did. other may do.

 

[Steve340]

Thanks I will watch the video and reply back.

 

[MoparCarGuy]

Pay special attention to the installation details for installing a fusible link wire in the path from the Alternator to the Starter Relay stud. The factory fusible link cannot be reused if you upsize your main Alternator output cable a.k.a. Charge Wire to the Starter Relay stud. The factory fusible link can remain in place if you left the original charge wire and added a parallel and larger AWG charge wire but the new charge wire must also have its own fusible link.

Most people plan for increased loads (see chart) and upsize the Charge Wire to #6AWG and use a #10AWG fusible link at the Starter Relay stud. The fusible link is four sizes smaller (numerically larger) and uses unique insulation that will melt instead of burn. The below charts are helpful with industry information for selection.

 

[72RoadRunnerGTX]

Some follow up detailed info for this older thread about that under-hood by-pass those who promote it don’t seem to want to talk about.

 

[Avalanche]

Great info

 

[Challenger RTA]

So here we go! This is in no order chronologically or technical. This is going to be electrifying! Scenarios of what should be done or not be done. Where loads should go. Where charging should go,cause and effect.
A fallow through.
This is the important part.
Thanks for posting the video on the site for other members to view. The battery and ammeters/melted bulkhead connectors are always an issue over time or an event. When the battery is connected current came flow both ways. Like when someone removes the charging wire, before they disconnect the battery and short the wrench to ground. There is a good chance the weakest point will be damaged, the connectors and maybe the wiring.

About the original charging and the load caring wire. In my opinion there should have been a fusible link right of the alternator sized appropriately. When engine is running it is a potential source of energy. Why the engineers didn't do it or maybe it was the bean counters. I think they were smarter then me.

As with any automotive production decision, most times, the bean counters were just as involved as the engineers, cost vs risk. I can tell you what the dealer training at the time had to say about circuit protection at the alternator. The 35-50amp alternators in use then just didn’t have to current potential to light up that 12 ga wire alternator output run, didoes or stator windings would open-up first on a wire dead short. The battery can light it up however, hence the fusible link close to the battery. That said, be sure to have circuit protection on any added, as close as possible to whatever source, even on anything directly connected to the alternator.

Packard terminals in the bulkhead connector? Indeed, have been a problem since new, by far the weakest link in the original system. Mainly on higher optioned models and vehicles having mis-placed loads added at the battery. IMHO, bean counters again, “click-together” connections at the firewall made for faster assembly, less cost. No one seriously designing something to handle this kind of current, with the intention for it to last, would do that. It used to annoy me to no end, when working on an old Mercedes, having unscrew screw terminals used throughout those cars, cost more to do that but they handled the designed current and lasted.

As for the modification suggestions, can’t disagree with any of it, all sounds like solid approaches. One thing in common however, the elimination of the original battery ammeter.

Any alternator upgrade deserves a total rethink of your electrical system.
I concur! In a Perfect World. you set it and for get it. Even a new harness or redoing the connections are not going to cover the variables that are going to happen.Nothing fused at splice 1 or at any other splice or connection.That are of high current.( There are no primary and secondary circuits.) It's out dated and antiquated. the proof is in the pudding ,connector 18 in the picture. seen it so many times. To bypass the ammeter in my opinion.YES by all means!

I posted the wiring diagram to help other that don't have the experience or understand of the battery and charging circuit.Did not include voltage regulator circuit to save any confusion. As JUAN VELDEZ Ask: 1 more than 60 amps, you should bypass the ammeter.Not just my opinion a fact the wiring and connections are not rated for not that much more than it was designed for an alt 37 -45 amps. age doesn't help. If it's rating was not exceeded it would be fine. Bulkhead connector 18 is the proof of over heating for what ever reason. // Now my opinion there are a few ways to do it. A: With out changing to much. It could be removed and add if you are going for show points. Run a heaver gauge wire 10 or 8 ( 8 ga would be better) to the the starter terminal or to the starter relay. Leaving the original wiring intact If it's good. this would remove the high charging load from the bulk head connector. But not the acc load from the charging circuit. That being said.The original charging circuit should have a fuse or fuse able link right off the alt to protect the wire.The acc load,headlights,parking light,wipers,blower motor,and others. The acc load would be drawn through connectors not fused 16 and 18 that is fused. As far as the ammeter You may not see any meter deflection.It would depend on the condition of the wiring.Less path of resistance on connector non fused 16 and 18 fused. And no the ammeter does not need to be removed. Now it is a bridge between,not really functioning but electrically hot. One terminal can be removed heat shrink or tape or cut off. As the charging will be going the 8ga wire. circuit 16 and 18 and everything else in tack as original as it always was. I will post an other scenarios allowing this to be absorbed by myself and other to comment or correct.I'm not perfect and we all can help on another. I listen to everyone 2 cents and sometime it's a sense

Alternators don't push anything? EMF = electromotive force or why is a charge voltage 13.7 - 14.1 for a 12 v battery?
"Electromotive Force is the amount of energy delivered per unit electric charge by a power source such as a generator or a battery (abbreviated E or EMF). As the generator or battery works on the electric charge being transported within itself, energy is changed from one form to another. The device's positive terminal becomes positively charged, while the negative terminal becomes negatively charged. The Electromotive Force is the work done on a unit of electric charge, or the energy gained per unit of electric charge. It is abbreviated E in the international metric system, but it is also known as EMF.

Now for the rest of the story. there a few ways to bypass the ammeter. considering that there is a 6 or 8ga wire to charge the battery. 1,I think the simplest way to bypass is to just move one of the wires over to the other amp gauge stud. The only thing in my opinion is that the current from the alternator is not fused.A fuse-able link right on the alternator. that would resolve that issue. 2,An other way to do it would be remove one wire from the ammeter. Heat tape over or use to feed an acc,other fuse box a voltage gauge. The problem with removing one wire is the is no connection to feed the battery side if there is no charging bypass. 3,This is what I did. An other opinion would be to connect to the starter relay with a fuse-able link or other to feed the alt balk head connector.Cut R6 from splice one and feed to the acc side of fuse box. Then there are two 20-25 amp circuits. I also cut headlight circuit from splice one and fused through fuse box. The only thing that is not fused yet the wiper motor from splice 3. Might piggy back on acc side fuse box or do an inline fuse,or add a small fuse box using one of the disconnected ammeter wires. I can't do that I cut them they were in bad shape! Keep in mind. If in good condition the disconnected ammeter wires can be used to feed other fused circuits. This is What I did or will do and feel comfortable with.your choice if you do it or not. Document fusing and keep in glove box for reference.

View attachment 92260

Wires running straight to the ammeter around the fuse box/bulkhead connector? You are describing a bulkhead charging system by-pass, by far the weakest link in the original design was routing the charging current through un-sealed, under current rated, Packard terminals. As mentioned, also referred to the fleet by-pass as the factory did this same by-pass on their fleet production (Taxis & Police) with larger alternators. Nothing wrong with this by-pass, do it on all my builds.

If the ammeter and insulators are in good shape and with proper connections, with the bulkhead bypass in place, no need for the engine compartment charge by-pass being suggested here. Especially running stock sized alternator and loads.

The headlamp switch is feed from two deferent places, B1 (headlamps) is spliced to Splice 1 as is the black lead to the ammeter, as are all other factory loads. B2 is fused at the fuse box and powers the running lights and dash illumination.

If you are wanting to reduce the load at the headlamp switch add the head light relays suggested above. However, connect the power feed to the headlight relays to the alternator stud, not the starter relay as pictured if running the ammeter correctly wired. No added loads at the battery/starter relay if running an ammeter. All loads need to be on the alternator side of the ammeter.

What relay is getting hot? Starter relay? What exactly is the issue you are trying to address

 

[Challenger RTA]

I’ll use 8ga for the charge circuit wires, and a single 12ga fusible link at the starter relay as I plan for running high output alternators and several additional non-stock loads, all on the alternator side of the ammeter. Another fusible link at the alternator is not necessary.
View attachment 102405Another

 

[Challenger RTA]

You might consider using CHR2889809_FOOT_PUMP_WASHER_GROMMET_2000__05967.
10 gauge or 8 gauge might fit through. I would protect it some how,fusible link,fuse,circuit breaker. each one if you run 2

View attachment 102404