Battery draining overnight

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The reason Powermaster wants you to run an 8 gage wire directly to the battery is because your ammeter and wiring was designed for 40 amps and the Powermaster alternator is claimed to put out 95. things could get ugly.
Diodes in an alternator can leak and cause a large current draw.

Did not see your post, ^^THIS^^
 
I’ve been reading the MadElectric article and I’m still a little confused. What I’ve been able to understand is this,
1. Disconnect everything from the ammeter.
2. Splice the two wires together that were on the ammeter.
3. Run an 8gauge wire from the alt to the starter relay. (Do I fuse this?)
4. Drill a hole in the big firewall harness plug thing where the red wire goes through.
5. Splice the red wire with fusible link into the wire it would’ve plugged into on the firewall connector.

Does this sound right? I’m trying to do this the best way possible while I’m in there because there’s nothing I hate more than wiring problems. Any input or pictures/diagrams will be greatly appreciated.
 
First thing I would do is remove the voltage regulator wire from the alternator and check for discharge.

My first thought was a bad or reversely installed diode in the alt.
This is a one wire alternator and the voltage regulator is no longer in the car
 
I’ve been reading the MadElectric article and I’m still a little confused.
Because they're a little confused. They think the alternator's main job is to supply the battery, and then the battery supplies everything else.
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This is a one wire alternator and the voltage regulator is no longer in the car
:BangHead:
Sorry, but when you have a problem and only post a portion of the information its very frustrating.
What year, model, engine and options were on the car to begin with?
What modifications, new electric items (fans, amplifier, EFI or whatever) have been done?
Does this sound right? I’m trying to do this the best way possible while I’m in there because there’s nothing I hate more than wiring problems.
IMO, the best wiring scheme for a non-modified '70-'74 with a higher capacity alternator is a the optional factory 60/65 amp alternator wiring I posted earlier in this thread. To that, add a headlight relay wire harness connected to the alternator. '66-69 would be similar.
But I also only see disadvantages to using a single wire internally regulated alternator, except for specific applications - like a tractor.
 
Sorry, but when you have a problem and only post a portion of the information its very frustrating.
What year, model, engine and options were on the car to begin with?
What modifications, new electric items (fans, amplifier, EFI or whatever) have been done?
This car is a clustertruck of everything. When I got it, it was just a half rolling shell. It’s a 1970 318 Duster with a 71 wiring harness with a carbureted 440 and a single wire alternator and electronic distributor. It has electric fans but they’re on a relay so they draw straight from the battery. Currently it has no electric devices inside other than the headlight and wiper switches. I plan on adding a nice stereo system later on. The headlights are not on a relay yet
 
You have a one-wire. You should be able to run a jumper direct from the alternator output to the battery ---with a fuse/ fuse link/ breaker for protection, and IT SHOULD NOT drain the battery. If that is a one wire, and disconnecting the alternator stopped the problem, then THAT ALTERNATOR IS DEFECTIVE

And as I said earlier, the people at wherever you bought it from should have known that
 
My favorite way to troubleshoot battery drains is to use a small bulb like a dash light. Get one with leads. Unhook your positive battery cable and put one wire on the unhooked battery cable and the other one to the positive battery post.

If you have a drain, the battery will light up. Unhook stuff till the light goes out.
 
My favorite way to troubleshoot battery drains is to use a small bulb like a dash light. Get one with leads. Unhook your positive battery cable and put one wire on the unhooked battery cable and the other one to the positive battery post.

If you have a drain, the battery will light up. Unhook stuff till the light goes out.

To add to this.......sometimes there are other things "on" or a large enough draw that the small dash lamp is very bright. Or the opposite, not enough to even light it.

So.........what to do?

Along with the dash lamp, also "rig" an old tail/ stop bulb and socket. This gives you several combinations. You can wire the two filaments in parallel (twist the tail/ stop wires together and use the lamp shell) for a large wattage test bulb

Use the lamp shell and the stop filament for a slightly lower wattage,,

Use the lamp shell and the tail filament for less yet,

Or use the two wires and leave the shell unconnected, which pust the two filaments in series, for a 'smallest' wattage.

AFTER you get the drain down to the dash lamp, or a "glowing" dash lamp, you can if you like, put your multimeter current (ammeter) in series with the ground, and find out how large the draw is.
 
Here’s my alternator. I’m trying to decide if I want to follow the guide that was previously posted on this thread or just send it in. The guy at Powermaster said if I sent it in they’d look over it and repair anything on it and just charge me for the parts. I tested it with an ohmmeter and it has continuity between the stud and case. If I were to open it up I don’t know what I’d do after that point.
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My favorite way to troubleshoot battery drains is to use a small bulb like a dash light. Get one with leads. Unhook your positive battery cable and put one wire on the unhooked battery cable and the other one to the positive battery post.

If you have a drain, the battery will light up. Unhook stuff till the light goes out.
I tried this when my alternator was hooked up and it was glowing bright. When I disconnected the alt, it went out completely
 
Hooking the 2 ammeter wires together will not fix your drain...all that does is take the ammeter out of the circuit, so you wouldn't have got the discharge indication on the ammeter at all.
 
It has electric fans but they’re on a relay so they draw straight from the battery.
Only when the engine is off.
Understanding this^^^ will be key to setting up trouble free circuitry.

Depending on how/when the fans will be running, may want to connect their power wire to a terminal stud from the alternator output.*
Whether to use a stock or aftermarket ammeter in the battery feed/charge circuit depends on how frequently and how long electrical accessories will be run on battery. If the battery is going to be deep cycled, then neither the factory circuit or a regular automotive starting battery is going to be happy for long. I'm describing describing long periods of discharging (running fans or an amp with engine off) and then resulting recharge cycles where the battery is sucking over 20 amps for a minute or more.


*Gray arrow pointing to a terminal stud used as a power distribution point.
Notice the alternator, ammeter and 6 gage wires are by a 10 gage fusible link at the first terminal stud.
Then the 10 gage and smaller wires and connections are protected by a 16 gage link (same as in a standard option wiring).
If other circuits with smaller wires were added to that same stud, then they too need protection.
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This is the other important point in your circuit design.
Protect the wiring with fuses, breakers, or fusible link based on the smallest wire or weakest link in the circuit.
Use a link where short term, higher current loads are to be expected, but protection against a battery short to ground is needed.
 
Without reading all the comments here is my advice and I may get a bunch of disagrees but i dont care it happened to me in my dart. Check your trunk light. I kept getting dead batteries and I changed everything batteries alt coil etc nothing helped I finally got a battery disconnect switch and turned it off at night. It was a solution but never fixed the problem. One day I had been driving around and went to the store I had some bags in the trunk, when I got home I reached in to get my bags and the light burnt my arm! I was thinking why is that light so hot how could it be hot in 2 seconds that the trunk was open then it hit me. It was staying on all the time the little switch was stuck I replaced it and never had a dead battery again.
 
Without reading all the comments here is my advice and I may get a bunch of disagrees but i dont care it happened to me in my dart. Check your trunk light. I kept getting dead batteries and I changed everything batteries alt coil etc nothing helped I finally got a battery disconnect switch and turned it off at night. It was a solution but never fixed the problem. One day I had been driving around and went to the store I had some bags in the trunk, when I got home I reached in to get my bags and the light burnt my arm! I was thinking why is that light so hot how could it be hot in 2 seconds that the trunk was open then it hit me. It was staying on all the time the little switch was stuck I replaced it and never had a dead battery again.
Trunk and glove box lights were a problem when I worked at the Buick dealer back in the 80's. Good call
 
Without reading all the comments here is my advice and I may get a bunch of disagrees but i dont care it happened to me in my dart. Check your trunk light. I kept getting dead batteries and I changed everything batteries alt coil etc nothing helped I finally got a battery disconnect switch and turned it off at night. It was a solution but never fixed the problem. One day I had been driving around and went to the store I had some bags in the trunk, when I got home I reached in to get my bags and the light burnt my arm! I was thinking why is that light so hot how could it be hot in 2 seconds that the trunk was open then it hit me. It was staying on all the time the little switch was stuck I replaced it and never had a dead battery again.
My Duster isn’t fancy enough to have a trunk light. But I did have basically the same issue on one of my Miatas
 
I think I’ve finally got my head wrapped around how the wiring works in these cars now. I went ahead and did the MAD bypass because of the horror stories I’ve read lately about the bulkhead connectors and factory ammeter melting (was able to neaten other wires in the process). I’ll just get an aftermarket ammeter when I make my new gauge cluster. Now that I have disconnected the alternator and done the bypass, everything is working and the battery no longer drains itself. Once I figure out what to do with my alternator I should be good to go.
Huge thanks to everyone that had input on this mess.
 
Only when the engine is off.
Understanding this^^^ will be key to setting up trouble free circuitry.

Depending on how/when the fans will be running, may want to connect their power wire to a terminal stud from the alternator output.*
What I should’ve said is that the fans are connected to the large stud on the starter relay (this is where my alternator wire goes) and will only turn on when the key is to the on position and engine is up to 185. So as you have taught me, they draw from the alternator.
 
I just got my alternator back from Powermaster earlier today. I bolted it on the car and hooked it up, all of my battery draining issues are GONE.
Huge thanks to Powermaster because they repaired and updated my alternator. They didn’t charge me a dime, not even for the return shipping. And it was 2 years out of warranty!
And they included stickers!
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