Found this writeup on how to convert your Amp gauge to a Volt meter.

BeepBeepRR · Sep 7, 2023

LOL got a second disagree on this... Either do it or don't its just a writeup by someone else and obviously it worked for the original article guy. Maybe its not for you, maybe it is. Either way its not something that has to be done its something that CAN be done if you want it. So to disagree with a writeup is pretty weird.

threewood · Sep 7, 2023

cj's mopar said:
I have a question about this .
Why can't you leave the stock wiring and amp.meter. Connected and just add a 10ga wire from the alt stud to the starter relay.
The alt will then still charge would it not ?

If the ammeter gasket is in good shape the easiest course of action would be eliminate the black and red bulkhead connectors and run solid wire or bolted connections. Loose fitting and corroded Packard connectors at the bulkhead are the issue.

I did the MAD bypass and have had zero issues. Also with the volt meter conversion. Both on my GTX. My Belvedere is stock, but the factory bulkhead connector is a bolt.

Daniel Foster · Sep 14, 2023

Jonas Nordstrom said:
Lmk @Daniel Foster why you disagree? I am always interested in improvements.
Though know that this system has worked flawlessly for over 6 years now.

Hey Jonas. I totally didn’t even see that I fat fingered the disagree button. Sorry about that. I don’t even know enough to disagree with you. Learning about all of this has made my brain melt so I appreciate the help.

Jonas Nordstrom · Sep 15, 2023

Daniel Foster said:
Hey Jonas. I totally didn’t even see that I fat fingered the disagree button. Sorry about that. I don’t even know enough to disagree with you. Learning about all of this has made my brain melt so I appreciate the help.

No worries. :thumbsup:

Though everything can be improved, I noticed that at idle when my electric fan starts then my rpm lowers.

chrger1967 · Jul 17, 2025

BeepBeepRR said:
Looks like its very doable for even a numb nuts like me. I have an old amp gauge and an old voltage gauge laying around I will see if I can do this with a video.

Gallery: How to Convert an Ammeter to a Voltmeter on the Cheap - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech

Moderator should sticky this link. Useful for lots of people.

Link to voltage gauge they used.
https://www.boschperformance.com/pr...lectrical-voltmeter-gauge-white-face-fst-8205

For my 67 Charger, my ammeter gauge is working fine I doubt if I can find a voltmeter that could be a close match. I've already upgraded the headlights to LED and plan on doing the same for all the bulbs in the car. That should have less of a draw on the cars wiring.

BeepBeepRR said:
This is not something you HAVE to do but just remember there is always a risk of melting the bulkhead connector somewhere in the future. So take it for what it is. The volt gauge modification would be perfect for this MAD modification if you bypass the amp gauge. You could then use a volt meter instead of the amp gauge to know your voltage. Thus the need for the gauge modification.

Even with the new harness. I would suspect the entire load of the vehicle going through that spade connector in the bulk head connector is still a potential for melting the bulkhead block. Even doing the bolt the wires together thing still puts that load going through that spade connector. I often wondered why in the MAD drawings they didn't just drill out the bulkhead block and run the wire straight through and still retain the amp gauge. But now I see why in Drawing B.

They pretty much just bolt the wires together and bypass the amp gauge. Looking at the drawings below they show the power distribution is cut short from the alternator and it goes directly to the starter relay.

This is why they no longer use the amp gauge. You cut out the weak link which is the spade connector.

But the way the MAD drawing shows they do more than just pass the wire through the bulkhead connector. Here is a link to the MAD page on the Amp gauge. Perhaps they word it better than me.

Catalog

Catalog

View attachment 1254372

View attachment 1254371

Now what if some relays were added for the headlights and maybe A/C, is any 12 volt accessory for that matter, wouldn’t that take away much of the draw on the wiring?

chrger1967 · Jul 17, 2025

BeepBeepRR said:
Looks like its very doable for even a numb nuts like me. I have an old amp gauge and an old voltage gauge laying around I will see if I can do this with a video.

Gallery: How to Convert an Ammeter to a Voltmeter on the Cheap - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech

Moderator should sticky this link. Useful for lots of people.

Link to voltage gauge they used.
https://www.boschperformance.com/pr...lectrical-voltmeter-gauge-white-face-fst-8205

For my 67 Charger, my ammeter gauge is working fine I doubt if I can find a voltmeter that could be a close match. I've already upgraded the headlights to LED and plan on doing the same for all the bulbs in the car. That should have less of a draw on the cars wiring.

davek said:
Let me ask you this,if all the wires are new why would I want to bypass the alternator gauge? I dont drive the Bee at night.The reason I ask is Im going to switch out my cluster with a restored one in a couple weeks.

How much of a draw could there really be with just driving on a dry sunny day? No wipers, headlights or heater. Although, a 100-amp boomer stereo system could draw allot of amps, NO?

72RoadrunnerGTX · Jul 17, 2025

chrger1967 said:
Now what if some relays were added for the headlights and maybe A/C, is any 12 volt accessory for that matter, wouldn’t that take away much of the draw on the wiring?

Not if you connect any of those added/modified loads directly at the battery or anywhere on the battery side of the ammeter, doing so will add current stress to the stock wiring. All loading needs to be on the alternator side of the ammeter if running a factory ammeter.
Suggest you check out some of the other pinned threads here if you want to understand this charging/electrical system.

davek · Friday at 3:43 PM

chrger1967 said:
For my 67 Charger, my ammeter gauge is working fine I doubt if I can find a voltmeter that could be a close match. I've already upgraded the headlights to LED and plan on doing the same for all the bulbs in the car. That should have less of a draw on the cars wiring.

How much of a draw could there really be with just driving on a dry sunny day? No wipers, headlights or heater. Although, a 100-amp boomer stereo system could draw allot of amps, NO?

I did the whole stereo system when I was young. Power for amps came right from the battery with a fuse. Had stock alt in my 69 charger. Same thing in my Tahoe,that had 2 12 inch kickers. No upgrade on alt.

Found this writeup on how to convert your Amp gauge to a Volt meter.

BeepBeepRR

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threewood

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Daniel Foster

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Jonas Nordstrom

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chrger1967

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chrger1967

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72RoadrunnerGTX

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davek

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