Does Alternator put out enough amperage

[Bartman]

I have a Taurus electric fan, an electric water pump, electric fuel pump, Air Conditioning, etc; and I'm using a stock LT1 alternator (which I think puts out 140 Amps or possibly only 124). I'm wondering if I need to upgrade my alternator to say a 200 Amp output.

 

When I'm running with everythying on, I don't think the alternator is putting out enough juice. I'm just running the stock Amp gauge and it looks like it's losing charge when everything is running including the lights. Could this be possible? How can I now for sure, a new alternator isn't cheap and I don't want to get another one if I don't have to.

[kcelectronics]

The standard alternator is rated at 45 amp so the only extra current is the fan and water pump, so 140A (even 124A?) should be more than enough.

Is the amp meter connected to the right place? It should really measure ALL current flow both to and from the battery with the exception of the starter motor current.

 

The amp meter may not handle this amount of current? As it uses a "shunt" to measure the current flow! and would be rated for not much more than the 45A of the stock system

 

This is one reason late models had a Volt Meter instead of the Amp meter.

[Bartman]

I did some more research, and my LT1 alternator appears to be a CS-130 which probably puts out either 100 or 105 amps. This is the max, so it puts out considerably less at idle.

 

The most common upgrade for these alternators is to switch to a CS-144, which can put out 140, 170, 200 or more amps. You can also upgrade the stock CS-130 to put out 140 or 170 amps, but it may be better to just get the CS-144 which should bolt right up and use the same connectors.

 

I'm going to call these guys Monday and see what they have to say.

http://www.alternatorparts.com/cs130_&_cs130d_alt.htm

[dapiper]

You will never flow 100 Amp thru stock harness, especially with fusible links.

[jeffp]

You have a very good question. You mentioned the electric components you are running and the current drain @ idle is really what you need to consider. A 100 Amp unit should be more then enough for your car, provided you don't have a stereo that draws 50-70 Amps wide open.

I have been working this problem for some time and have inveated to date about 1000.00 in various alternators and units. The last unit I have bought was a powermax 150 Amp unit. The alternator does very well, EXCEPT, in the case of idle current it can provide.

Alternators can be configured to put out alot of current, but the majority of them will not give you the idle current you will need. There in lies the problem. In my case, the alternator will provide the current needed for my water pump, ECU, electric fan, fuel pump, injectors, ignition. As soon as I try to run anything else(at idle) the voltage drops to about 11.6-12 volts. So if you are fuel injected, the injectors become mushy, and the car runs poorly because there is not enough current to properly open and close the injectors.

So that is the real issue. I am looking at a unit, and it is being shipped to me, that according to the seller will provide overal 200 Amps of current, plenty of power there, but it will also provide 90-95 Amps of current @ idle, now your talking. So we will see how it does. The unit is a GM part, internal regulated, and will not be to difficult to retrofit to the stock nissan bracketry. The housing is 6.5" in diameter, larger then a standard unit. The part is 269.00 with tax and shipping. This is much cheaper then the powermax unit that cost me 450.00 for the unit, and since the regulator was not that good, another 140.00 for a good regulator. So you can see this stuff gets expensive very quickly. I also did a 105 Amp upgrade to the stock nissan unit for 218.00 and it also will not provide enough current @ idle. This is the third go around on the alternator solution, and I am hopeful this third try will get me the results I am looking for. So to select a correct part, you really need to do a current draw test to see just how much current you need @ idle, then size the alternator accordingly. Don't worry about the higher current ratings of the units out there as the regulator will determine the current required to charge the battery sufficently. hope that helps

[Bartman]

You have a very good question. You mentioned the electric components you are running and the current drain @ idle is really what you need to consider. A 100 Amp unit should be more then enough for your car' date=' provided you don't have a stereo that draws 50-70 Amps wide open.

I have been working this problem for some time and have inveated to date about 1000.00 in various alternators and units. The last unit I have bought was a powermax 150 Amp unit. The alternator does very well, EXCEPT, in the case of idle current it can provide.

Alternators can be configured to put out alot of current, but the majority of them will not give you the idle current you will need. There in lies the problem. In my case, the alternator will provide the current needed for my water pump, ECU, electric fan, fuel pump, injectors, ignition. As soon as I try to run anything else(at idle) the voltage drops to about 11.6-12 volts. So if you are fuel injected, the injectors become mushy, and the car runs poorly because there is not enough current to properly open and close the injectors.

So that is the real issue. I am looking at a unit, and it is being shipped to me, that according to the seller will provide overal 200 Amps of current, plenty of power there, but it will also provide 90-95 Amps of current @ idle, now your talking. So we will see how it does. The unit is a GM part, internal regulated, and will not be to difficult to retrofit to the stock nissan bracketry. The housing is 6.5" in diameter, larger then a standard unit. The part is 269.00 with tax and shipping. This is much cheaper then the powermax unit that cost me 450.00 for the unit, and since the regulator was not that good, another 140.00 for a good regulator. So you can see this stuff gets expensive very quickly. I also did a 105 Amp upgrade to the stock nissan unit for 218.00 and it also will not provide enough current @ idle. This is the third go around on the alternator solution, and I am hopeful this third try will get me the results I am looking for. So to select a correct part, you really need to do a current draw test to see just how much current you need @ idle, then size the alternator accordingly. Don't worry about the higher current ratings of the units out there as the regulator will determine the current required to charge the battery sufficently. hope that helps[/quote']Keep us posted on the "third go around". It sounds like we have similar needs, and that is to get more current at idle. I have a new alternator on its way that should deliver around 90 amps at idle, which should provide enough current. It sounds like you're probably getting the same cs144 unit that I'm getting, but with a higher max output. From what I understand the idle output is essentially the same for all the CS144's but you can get them with higher maximum outputs like 140, 170, 200, and even 250 with a dual rectifier.

 

Here's a quote from the FAQ at QuickStart:

The best way by far to obtain more power at lower engine speeds is to install an oversize alternator. The physically larger alternators produce more power at lower engine speeds and are much more reliable at higher outputs. Installing a higher output alternator that is the same size as your original alternator will not give you more power at idle.

http://www.alternatorparts.com/FAQ.htm#what