Alternator install help

[D35 Torpedo]

6 hours ago, 38plymouth said:

60 amps. And there is no way a stock generator is powering 6 volt lights as bright as 12 volt. My generator worked fine but a bearing started making noise. I personally cleaned every connection in the system before adding the alternator and it is still a night and day difference. At idle or low rpms with the lights on and fog lights on they were very dim until yoi8u increased the rpms. With the alternator they are the same at idle as they are at all rpms. And they are brighter. This swap is a no Brainerd if you actually drive the car.

I daily drive my car. Through snow and rain. 50 watts is 50 watts. They are just as bright.

 

7 hours ago, Sam Buchanan said:

 

Let's clear up one item up front. It is obvious that you are very pleased with the generator system on your Plymouth and that is fantastic. I'm happy for you. 

 

I am also pleased with the alternator charging system on my P15. That is also fantastic, but it seems you are not so happy for me.   

 

Yes, my alternator definitely puts out more voltage than the old generator because it was......DEAD, even after two regulators!  ?

 

The alternator under light load puts out 7.5v at idle, with all lights that drops all the way down to......7.2v at idle. In regard to the ammeter in my car, here is what it looks like when idling with lights on.

 

 

 

I haven't verified the accuracy of the ammeter, don't really care to since I place much more value on the verified voltmeter. The highest I've seen the ammeter after a cold start is an indicated 20a for less than 30 seconds as it declines to about 10a for a few minutes then back down to what you see above. I've never calculated total load on the system, never seen the need to since everything seems happy and the battery stays hot.

 

The wiring in my car has received considerable attention and new grounds have been established on the head and taillights. The lights are bright, don't dim at idle.....and I like them. The wiring and alternator have been perfectly reliable since I returned the car to service three years ago after extensive shop time.

 

 

Dude..I'm stating a point based on simple math. Good for you. I understand the benefits found with an alternator. It's undisputeable. You really seem focused on idle performance. But 99% of the time driving, you are not at idle. My ammeter shows 5-10 amps at idle as well. But that's because it simply cannot make anymore. There is no way a generator is better than an alternator, but my car was originally equipped with it, and I've made the best of it. I don't care how you might feel when I state a point. It's not about your feelings, it's about facts and truth. 

[38plymouth]

2 hours ago, D35 Torpedo said:

I daily drive my car. Through snow and rain. 50 watts is 50 watts. They are just as bright.

 

Dude..I'm stating a point based on simple math. Good for you. I understand the benefits found with an alternator. It's undisputeable. You really seem focused on idle performance. But 99% of the time driving, you are not at idle. My ammeter shows 5-10 amps at idle as well. But that's because it simply cannot make anymore. There is no way a generator is better than an alternator, but my car was originally equipped with it, and I've made the best of it. I don't care how you might feel when I state a point. It's not about your feelings, it's about facts and truth. 

Except you aren't getting 50 watts most of the time. Where I live and drive sitting in the suicide lane at night trying to turn with dim lights and a black car makes you a target. They aren't dim at idle anymore. Your generator simply isn't capable of the same performance.  It's awesome that you are happy with your car though.

[soth122003]

It's because the alternator puts out a consistent rate at all rpm's. The generator has to maintain a certain rpm to reach full output and idle speed ain't it. That's why most cars with a genny have an idle speed knob and linkage for slow or stopped traffic.

 

Joe Lee

[D35 Torpedo]

7 hours ago, 38plymouth said:

Except you aren't getting 50 watts most of the time. Where I live and drive sitting in the suicide lane at night trying to turn with dim lights and a black car makes you a target. They aren't dim at idle anymore. Your generator simply isn't capable of the same performance.  It's awesome that you are happy with your car though.

50 watts are the high beams. I'm usually using the 40 watt filament. I've only noticed dimming when the battery was running low. I had charging issues when I got the car. And I'm glad you're enjoying yours as well. I was considering an alternator until I fixed what I have, now I'm quite content. It's fun to tell people it has a generator and 6 volt positive ground system. I'm an electrician by trade, so I'd rather fix it.

[maok]

8 hours ago, soth122003 said:

It's because the alternator puts out a consistent rate at all rpm's. 

 

Joe Lee

 

Actually, alternators vary in their output (current/amp) at varying rpm as well, though much more than a generator.

 

Generally, at about 2000rpm an alternator can only output about half its max output ie 60amp alternator has only about 30 amps available. This will vary from alternator to alternator. Usually a new alternator will come with a data performance sheet, check it out.

 

When you install an alternator, you need to increase your idle speed to over 600-650rpm for it supply some amps. Try turning down the idle speed below 500rpm and observe your ammeter.

[D35 Torpedo]

Tonight driving home I was paying more attention to my instruments and lights. The Ammeter was holding almost 20 amp, even at idle. I'm guessing the idle is 450- 500 rpm. And when I got home I shut the engine off without turning the lights off. They did not dim. Fired it back up and they didn't get brighter. My conclusion is that headlights dimming is as much a battery thing as is a generator thing.

[Sniper]

10 hours ago, D35 Torpedo said:

The Ammeter was holding almost 20 amp, even at idle.

 

That isn't right.  Assuming we are talking about  along term 20A indication.  More than a few minutes.  Either that or you have some load wired on the battery side of the ammeter, which you should not.

[D35 Torpedo]

1 hour ago, Sniper said:

 

That isn't right.  Assuming we are talking about  along term 20A indication.  More than a few minutes.  Either that or you have some load wired on the battery side of the ammeter, which you should not.

I had the headlights on. Them and the markers draws almost 20 amps. 

[Sniper]

1 hour ago, D35 Torpedo said:

I had the headlights on. Them and the markers draws almost 20 amps. 

 

Your headlights should not be wired to the battery side of the ammeter by doing that you have effectively made the ammeter useless as a gauge.

Edited April 4, 2023 by Sniper

[D35 Torpedo]

11 hours ago, Sniper said:

 

Your headlights should not be wired to the battery side of the ammeter by doing that you have effectively made the ammeter useless as a gauge.

If they were wired to the battery side. The ammeter wouldn't react to the headlight draw. I'm not following you. I followed my diagrams closely. I will double check tomorrow to verify that I wired the braker properly...

[maok]

56 minutes ago, D35 Torpedo said:

If they were wired to the battery side. The ammeter wouldn't react to the headlight draw. I'm not following you. I followed my diagrams closely. I will double check tomorrow to verify that I wired the braker properly...

 

If your ammeter is showing +20amp charge when you turn the lights on then the alternator is supplying the power through the ammeter across to the battery side then to your lights. Sniper is correct, you need to check your wiring.

 

Ammeter simply shows which way the current/amps is flowing. When discharging, its going from battery to ammeter then to your circuits, when charging, its going from alternator to ammeter then to your battery ie after starting your engine with the starter motor. When your battery is fully charged the alternator is supplying all the amps to your circuits.

[Sniper]

With the exception of the horns and during normal operation, the only current flow thru the ammeter should either be the the charging current to top off the battery when the engine is running or the battery supplying power when the engine isn't running.  If the charging system isn't doing it's job then the battery gets tapped to supply the deficit.  That is when you see a negative amp reading.  This is a diagnostic tool that helps you realize you have a problem.  When you have a continuous load, light the headlights, wired to the battery side of the ammeter you will always show a negative reading, which negates the diagnostic function.

 

Remember the battery's only job is to start the car and to make up the deficit when your charging system cannot handle the load and the ammeter's only job is to measure the current into or out of the battery.

[Sam Buchanan]

On 4/3/2023 at 11:11 PM, D35 Torpedo said:

Tonight driving home I was paying more attention to my instruments and lights. The Ammeter was holding almost 20 amp, even at idle.

 

Sounds like this ammeter is wired to function as a loadmeter.

 

2 hours ago, Sniper said:

With the exception of the horns and during normal operation, the only current flow thru the ammeter should either be the the charging current to top off the battery when the engine is running.......

 

Like this:

 

[D35 Torpedo]

On 4/5/2023 at 7:00 AM, Sam Buchanan said:

 

 

 

 

[D35 Torpedo]

On 4/5/2023 at 7:00 AM, Sam Buchanan said:

 

Sounds like this ammeter is wired to function as a loadmeter.

 

I think so

 

On 4/4/2023 at 11:17 PM, maok said:

 

If your ammeter is showing +20amp charge when you turn the lights on then the alternator is supplying the power through the ammeter across to the battery side then to your lights. Sniper is correct, you need to check your wiring.

 

Ammeter simply shows which way the current/amps is flowing. When discharging, its going from battery to ammeter then to your circuits, when charging, its going from alternator to ammeter then to your battery ie after starting your engine with the starter motor. When your battery is fully charged the alternator is supplying all the amps to your circuits.

I must have. It doesn't show a draw with lights on and engine off

 

Thanks guys, I'll check it out.

[D35 Torpedo]

On 4/5/2023 at 4:17 AM, Sniper said:

With the exception of the horns and during normal operation, the only current flow thru the ammeter should either be the the charging current to top off the battery when the engine is running or the battery supplying power when the engine isn't running.  If the charging system isn't doing it's job then the battery gets tapped to supply the deficit.  That is when you see a negative amp reading.  This is a diagnostic tool that helps you realize you have a problem.  When you have a continuous load, light the headlights, wired to the battery side of the ammeter you will always show a negative reading, which negates the diagnostic function.

 

Remember the battery's only job is to start the car and to make up the deficit when your charging system cannot handle the load and the ammeter's only job is to measure the current into or out of the battery.

Thanks Sniper

[D35 Torpedo]

Sure enough. The braker was on red. Live and learn I guess. The ammeter is acting the way it should. Thanks for alerting me to this.

[clarkede]

18 hours ago, D35 Torpedo said:

Sure enough. The braker was on red. Live and learn I guess. The ammeter is acting the way it should. Thanks for alerting me to this.

What kind of breaker did you install and where in the circuit?  I'm going to presume you put it between the battery and the ammeter.  Did you place it on the firewall somewhere or inside the passenger compartment?  I recently rewired my entire 48 and added in a couple fuse panels.  Then I had problems with my generator and I replaced it with an alternator - which is running great and I am so glad I did.

[D35 Torpedo]

On 4/8/2023 at 11:05 PM, clarkede said:

What kind of breaker did you install and where in the circuit?  I'm going to presume you put it between the battery and the ammeter.  Did you place it on the firewall somewhere or inside the passenger compartment?  I recently rewired my entire 48 and added in a couple fuse panels.  Then I had problems with my generator and I replaced it with an alternator - which is running great and I am so glad I did.

It's the factory breaker that mounts on the back side of the gauges. It protects the lights. I fused everything else.