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Ammeter bypass

dodge68charger

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I recently sent my instrument cluster to auto instruments to get restored and they converted my ammeter to a voltmeter. The instructions said to find a 12 volt source for the voltmeter and splice the red and black wires that went to the ammeter together to complete the circuit. I was just wondering if i shouls connect the red n black wire together before the bulkhead connector, i heard of the bulkhead connector heating up and melting and the spade connectors are a weak point. Thanks
 
If you connect the two wires together inside the car (under the dash) you are essentially doubling the gauge of the positive feed wire to the dash - by using both wires to carry the current. That is already a big help over the factory setup. If you then do a headlight relay mod (go to Madselectronics.com, or there's an Allpar page on it), you'll have taken a huge amount of amp draw out of the dashboard. At that point I think you're pretty safe.

I haven't thought about the idea of combining the two wires in the engine bay instead of under the dash. Hmmm....
 
Should i take any precautions if i splice the red and black wire together in the engine compatment. Ie. inline circuit breaker. Thanks
 
You need to bypass it at the amp meter itself. By-passing at the bulkhead will bypass power to everything inside.
A real good and easy way is to land both the red and black under the same terminal post on the meter.
 
Marks is correct. The one danger of mounting both wires to one post on the ammeter (as I see it) is that the post is still VERY close to the grounded chassis of the meter, and the post itself is not that reliable (ask me how I know). If that post with the two wires snaps off and touches ground, you got smoke. I chose to simply cut the ends off the two wires, connect with a butt connector and solder. Cover with shrink wrap and a protective sleeve of split-loom to make SURE they don't ever touch a ground.
 
Thanks guys. I'm gonna head to the shop and tie them together under the dash, thank god its outta the car. Anything i can do to kinda lessen the load of amperage goin through those wires, should i use bigger wire somewhere else. Thanks
 
Marks is correct. The one danger of mounting both wires to one post on the ammeter (as I see it) is that the post is still VERY close to the grounded chassis of the meter, and the post itself is not that reliable (ask me how I know). If that post with the two wires snaps off and touches ground, you got smoke. I chose to simply cut the ends off the two wires, connect with a butt connector and solder. Cover with shrink wrap and a protective sleeve of split-loom to make SURE they don't ever touch a ground.

^ Pretty sure this just happened to me ^ almost set the car on fire..... Dodge68charger - what did you come up? did you just skip the ammeter and connect the wires together (heavy gauge red and black) and then run the heavy black alternator wire to you starter relay??
Im about to do this upgrade - just my confidence is not quite up there yet... Im not a big fan of electricity - and the latest "flash fire" scared the crap outa me haha.
 
Amp meter bypass

Marks is correct. The one danger of mounting both wires to one post on the ammeter (as I see it) is that the post is still VERY close to the grounded chassis of the meter, and the post itself is not that reliable (ask me how I know). If that post with the two wires snaps off and touches ground, you got smoke. I chose to simply cut the ends off the two wires, connect with a butt connector and solder. Cover with shrink wrap and a protective sleeve of split-loom to make SURE they don't ever touch a ground.

Im new to this forum stuff and hope im doing it right. Anyway, thanks for the info in your post about the amp meter bypass.
 
Rather than cut off the lugs, I would put a nut and bolt through the two to join together. Then heat shrink with good quality stuff. This will be a good joint and will never give you grief and you don't need to cut the original wires.
 
I like the ammeter functioning so I ran a new 10ga from the alternator through the firewall directly to the ammeter bypassing the bulkhead connectors. Disconnected the original 12ga at the alternator. Ran a new 10ga from the ammeter through the firewall to the battery stud with a fusible link. Original 10ga red wire is in place but taped off in case I want to return to original. The original 12ga from the ammeter is still in place to power the interior. Think this was called the fleet bypass that was used for police, taxi use. Now both charge wires bypass the bulkhead connectors. I use headlight relays powered from the alternator which is the original unit.
 
OK, in the meantime I just disconnected the ammeter. That will reduce the risk of fire right? If it is not charging it won't start. Otherwise don't care right now.
 
Rather than cut off the lugs, I would put a nut and bolt through the two to join together. Then heat shrink with good quality stuff. This will be a good joint and will never give you grief and you don't need to cut the original wires.

That is what I did as I didn't want to to cobble up my new dash harness when I rebuilt my '66 Ply Sat. I also used a fuseable link with it as recommended by the MAD Electric Upgrade and By Pass. The Ammeter is none functioning and I installed a Voltage Gauge through a fused Bus Strip to run my gauges and all. Really easy to do...cr8crshr/Tuck
 
I disconnected the black and red wires from my ammeter in my 71 cuda and bolted them together and taped them up heavily, leaving the connection tucked up just behind the gauge. Works well, but I also did the starter relay bypass and headlight relay upgrade from crackedback.
Going carefully over my recently purchased 72 runner, it is in need of the same "upgrades", so I ordered the kits again, but this time I want to keep the ammeter functional with the "fleet bypass" described above.
 
Jumpering the red and black together IS NOT ENOUGH, and it does nothing to fix the problems in the bulkhead connector

Please read this article, there is no sense in me re-writing what is good info

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

Another way around this is the way Ma originally did what has become known as "fleet police taxi" wiring used on 60? -65A optional ammeters. On those cars, heavier ammeter wires were run through separate grommets in the firewall. This is in some of the shop manuals, and you can download quite a few at MyMopar
 
Another way around this is the way Ma originally did what has become known as "fleet police taxi" wiring used on 60? -65A optional ammeters. On those cars, heavier ammeter wires were run through separate grommets in the firewall. This is in some of the shop manuals, and you can download quite a few at MyMopar

Okay...need to ask a dumb question...

I have a copy of the 'fleet/taxi' wiring bypass diagram. It's also for 64s, like I've got. Question is on the regulator. Even on the 64 wiring, the fleet diagram shows using one of the later transistorized(?) regulators. Is that a must, or will the bypass work using (lol) one of the regular regulators???
 
I fused the wires internally but ran a separate 10 gauge wire to the interior and back essentially bypassing the connectors in the bulkhead plug. I think this is the only way to prevent a meltdown at the terminals of the firewall plug and done properly is not really noticeable. Once you bypass the amp gauge internally it's the contacts in the bulkhead connector that become the weak point and therefore subject to arcing.
 
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