Author Topic: Discharge question about my Amp Meter  (Read 1655 times)

Offline wally426ci

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Discharge question about my Amp Meter
« on: July 14, 2009 - 12:27:00 PM »
Night time:

Lights on, On the mark, but slightly left of the center line

Hit the Brakes and it dives by at least 1 notch and as you sit at a red light it stays low until you gas it

Flickers with the Turn Signals.

Any ideas? Its been that way for a while. My uncle said maybe ground, I thought maybe I need a stronger alternator. Not sure what Amps I have right now.

 :working:
{OOI====I====IOO}
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      [O[]=====[]O]
      '68 D100




Offline Chryco Psycho

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Re: Discharge question about my Amp Meter
« Reply #1 on: July 14, 2009 - 01:15:46 PM »
sounds normal to me , most of our cars don`t spin the alt fast enough at idle to keep up with all the lights & wipers on

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Offline wally426ci

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Re: Discharge question about my Amp Meter
« Reply #2 on: July 14, 2009 - 01:27:38 PM »
Whew! thats what i was hoping. I figure it charges enough at cruise to keep it up. thanks man!  :cooldancing:
{OOI====I====IOO}
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      [O[]=====[]O]
      '68 D100

Offline B5barracuda

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Re: Discharge question about my Amp Meter
« Reply #3 on: July 14, 2009 - 07:01:47 PM »
easy fix is upgrade to a 110 amp alternator  :2cents:
2010 CHALLENGER S/E DEEP WATER BLUE
1970 CORONET 440 FOUR SPEED 30K ORIG MILES
1969 SUPERBEE 383 AUTO 99 PAINT CODE
1996 INDY RAM PACE TRUCK

Offline Chryco Psycho

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Re: Discharge question about my Amp Meter
« Reply #4 on: July 14, 2009 - 07:03:36 PM »
you will need to modify the wiring a bit for a 110 amp

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Offline Bullitt-

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Re: Discharge question about my Amp Meter
« Reply #5 on: July 14, 2009 - 07:22:16 PM »
Mine had got that way back when it was my daily driver in the '70s.  I burnished every connection & ground I could find from the alt. to the voltage regulator to the battery, & except when everything was on like defroster, wipers & headlamps, cured mine.. Come to think of it I think I changed my alternator brushes at some point also.
Wade  73 Rallye 340..'77 Millennium Falcon...13 R/T Classic   Huntsville, AL
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Offline 05srtcuda

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Re: Discharge question about my Amp Meter
« Reply #6 on: August 18, 2009 - 12:37:05 AM »
Currently having similar problem on my '70 cuda (4-sd).In the day ,driving the cuda is fine.At night though kinda similar problem your experiencing.Under load the alternator is charging, but when I come to a light or stop sign and take it out of gear the amp meter reads a little bit less then half and the headlights and dashlights get really dim and the motor wants to die.I have to rev the engine to keep it from dying.My friend says it the headlight switch.I recently changed the stock alternator to a 75amp Powermaster alternator and drove it at night .It helped some what to the point that the motor didn't want to die out ,though the headlights and dashlights still were still kinda dim but not as bad when I ran the stock alternator. The amp meter stayed right in the middle.I might try to buy a new voltage regulator and see what happens.
« Last Edit: August 18, 2009 - 12:39:05 AM by 05srtcuda »

Offline Chryco Psycho

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Re: Discharge question about my Amp Meter
« Reply #7 on: August 18, 2009 - 01:26:34 AM »
the reg is not the problem , the reg will switch to charge as soon as the load exceeds the imput from the aly , you neeed to spin the alt faster with a smaller pulley or switch to a modern 100 amp alt but you need to adda jumper from the Alt ouput to the power stud on the start relay to take some of the load off the ammeter & bulkhead connections

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Offline dodj

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Re: Discharge question about my Amp Meter
« Reply #8 on: August 18, 2009 - 08:43:58 AM »
the reg is not the problem , the reg will switch to charge as soon as the load exceeds the imput from the aly , you neeed to spin the alt faster with a smaller pulley or switch to a modern 100 amp alt but you need to adda jumper from the Alt ouput to the power stud on the start relay to take some of the load off the ammeter & bulkhead connections
:iagree:These cars were designed to have ALL the alternator output go through the bulkhead connector, through the ammeter, then back through the bulkhead connector to the start relay to charge the battery. The wire is #10awg - rated for 30 amps. A 100 amp alternator will sooner or later melt the bulkhead connector, or ammeter in the dash. The ammeter has the potential to cause a dash fire. Wiring modifications are a must if you are going to up the alt power output. It's a good idea to update the wiring (charging cct, headlight cct) for safety and reliability even with a stock size alt.
Scott
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Offline BruteForce

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Re: Discharge question about my Amp Meter
« Reply #9 on: August 18, 2009 - 01:25:35 PM »
The stock alternator wire is actually 12 gauge, not 10.

Offline dodj

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Re: Discharge question about my Amp Meter
« Reply #10 on: August 18, 2009 - 04:05:00 PM »
The stock alternator wire is actually 12 gauge, not 10.
oops :clueless:
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline duodec

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Re: Discharge question about my Amp Meter
« Reply #11 on: August 19, 2009 - 01:25:38 AM »
The later '70s Mopar alternators with the thin stator (gap between front and rear case halves is very small and you don't see the laminated edge of the stator ring between them) tend to have better low RPM output than the older units.  They look pretty close to the older squareback ones too, except for the thin stator.  Of course with rebuilds who knows what you are getting.  We replaced the original alternator in our '69 Custom Suburban with a new thin stator (and a replacement electronic voltage regulator and the discharge at idle issues improved measurably.  The work was done because we were towing trailers, had extra lights in the circuit as a result, so the discharge was noticeable.

I wish I still had that car...