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Why bypassing the ammeter is a GOOD idea!

patrick66

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In 2010, I was at the end of a 275-mile trip in the Coronet, at night. As I drove down the off-ramp, the lights became very dim and the car started running like crap. Then my low beams quit. Now I have to go the last 1-1/2 miles on high-beams and keeping the throttle feathered to keep the car running. I thought I caught a whiff of something electrical. Ah, hell no!

I felt that the ammeter had fried. Indeed, it had. So I did the ammeter bypass operation, but kept the disconnected ammeter in the dash.

This week, I replaced that with a good one, even though I had no intention of ever reconnecting it.

Here are a couple of pics of the old one, completely fried. If you are having the urge to bypass yours, don't dick around! Bypass it!!! I've got a voltmeter installed on the Coronet, and though it won't give you the charging info an ammeter provides, I trust the voltmeter. I'm damn lucky I didn't burn the car to the ground!
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The ammeter didn't fail, but the isolation gasket did. It got craked due heat and missed the piece with car vibrations, so is not really an ammeter gauge failure. You need to take care of the electric parts like everybody takes care of brakes or carbs, which also gets gaskets stressed and you tipically replace. When you get an oil valve seal failure, you simply replace them, and don't blame the valves! Or do you?

With the propper checkouts on an old car and correct mantenience, you can get your ammeter running safe forever.

Just need to take serious your car electrical like the rest of the car everybody does.

STOP MINIMIZE THE ELECTRICAL PARTS OF YOUR CARS!

;)

Then also get the correct charging balance which IS NOT the factory setup... they really did a big mistake on alt outputs rates from factory.
 
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and actually, the ammeter is not fried... just need a good clean, get the stud tightened back to the shunt and will live forever.

Trust me, an ammeter is a gauge allmost imposible to beat up to the death.
 
Looking at the theory behind the ammeter, it makes sense to eliminate it. The cars were not expected to be still used 50 years later, right?
When new, all connections were clean, wires had no corrosion and everything worked great. Add a few decades of heat, cold, dust, humidity and general wear and even the most trusty designs can fail.
Having charging current run through the firewall by way of a thin spade connection just seems risky doesn't it?
I bypassed the ammeter in my Charger when I added the Dakota Digital gauge cluster. I did it in my 75 Power Wagon last year. I still intend to do this to my other cars as well.
 
All of the charging current still goes through the bulkhead connector, and with the ammeter bypassed, there's no need for that. Run a heavy gauge wire from the output stud on the alternator to the battery or starter relay. Some Charging current will still go through the bulkhead connector, but it'll take the path of least resistance, so most will go though the new wire.
 
Having charging current run through the firewall by way of a thin spade connection just seems risky doesn't it?
This is the most important consideration for anyone touching the wiring on these older cars.

I bypassed my ammeter the easy way - put both terminals under the one stud, and ran a fused heavy gauge cable direct from the alternator output to the starter relay stud. I don't show any charge on my gauge, but I now also get brighter headlights and a lower risk of fire through the likes of the lighting dip-switch and headlight switch. Before rebuilding my GTX, the dip-switch molded connector had been seriously hot and partially melted.
 
Looks like a bad connection got loose.
Were your headlights on?
It's was at night.
Hot stuff.
Long time in the works.

My position is to do a head light mod and take the load off the AMP meter.
That fixes several weak points at once.
Including Ampophobia.
But I guess that's not OE.
Funny, that.
 
All of the charging current still goes through the bulkhead connector, and with the ammeter bypassed, there's no need for that. Run a heavy gauge wire from the output stud on the alternator to the battery or starter relay. Some Charging current will still go through the bulkhead connector, but it'll take the path of least resistance, so most will go though the new wire.

The straight path between alt and starter relay stud and what still goes throught the bulkhead is not JUST about the less resistance path, is about where is the load sucked in and how many paths you got to feel the load demand.

IF YOU CUT the batt load demand because keep it full with a GOOD ALT FEEDING THE CAR never requesting load from batt, then you can get OR NOT the straight path between them, the load going throught will be nearly 0 either with weak molex terminals and 16 gauge wire or a straight wire no terminals on 8 gauge wire. THIS IS the real deal. If you make that the ammeter will barelly get load through it. No load, no heat. No heat, no damage, everywhere, not just on ammeter.

The car load demand will be allways the same ( average ) at main splice with a poor alt or a good alt. Having a good alt just will need to keep good conections to feed the main splice into the cab. Even with stock bulkhead conections you can be safe on packard terminals with a GOOD power plant on a good alt, but JUST IN CASE is better get a bulkhead terminals bypass ( or a parallel path... if bulkhead is still good, no need to remove them ), which is not the same than an ammeter bypass
 
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I still have my amp gauge, and I like it.
 
My position is to do a head light mod and take the load off the AMP meter.

Forgot to mention... true statement JUST if relays are sourced from alt side of the game and still on an upgraded alt.

Even without relays, will save the amm just on a good alt upgrade, just the headlight switch will be still handling the load, but that won't care to the amm. The amm will register the same with or without relays. It won't care that. The beams will ( or will try ) to suck the same with or without them.
 
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When it comes to safety, security and the obvious....OE is a not important.....All my clusters get the volt conversion and it is a one and done, peace of mind scenario....

If a judge wants to peak his head under my dash and ding me for a common sense alternative(which is hidden very well btw)....So be it....I have plenty of points as it is on the rest of the GTX...keep in mind no one has scored a 100.....lol....

But hey at the cost of a volt conversion is pennies on the dollar in comparison to the full restoration....The added cost in my books is money well spent for cheap protection....
 
I don't trust inline ammeters. They may be fine for a long time then "what's that smell?".
A better design to monitor current is to use a current transformer like we do in the industrial world.
 
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