Dearborn5.0

I've heard two things that make me want to get an anmeter. Are these true?

1) stock 2G alternators only put out 88 amps at max, and at engine idle, its lower perhaps 40 amps. And your alternator can put out 14.7V all day, but if it does not put out enough amps at idle, the battery will discharge.

2) Anmeters show how many amps go to the starter during cold start. The goal is to keep the voltage high and the amps low. Because too many amps will wear the starter over time.

Are these facts true?

How do you safely install an anmeter? if you just mount it to the fender its going to short to ground....

Is it better to mound the alternator between the battery + and starter solenoid? or on the alternator into battery wires?

can you mound the anmeter between chasis/engine ground and battery - and get a measurement of amps flowing as well?

FiveLiterRiceEater

ammeters need to be mounted inline with the circuit.


so if you want to hook one between the battery and alt. then you need a wire going from the alternator, to the ammeter, to the battery. no grounds.

the starter would be the same way.

Dearborn5.0

I agree

FiveLiterRiceEater

dont mount it on the ground side.

all you really need to do is mount it into the alternator wire going to the battery.

r.barn

yes it's the amps that power stuff. thats why you can take a 50,000volt TASER
blast and it doesnt kill you, cause the amps are low.

you dont really need an ammeter. yes the stock alternator (75amp) sucks
but jegs and 50resto have nice 100amp direct replacements that would
take care of any worries and supply all the power you'd ever need.

just stick with factory wiring system

Dearborn5.0

how many amps does the car need to function (run)?

FiveLiterRiceEater

that depends on how much crap you have to power at one time.


if you have a big system, lights, and air conditioning on at the same time at idle, you're going to be close to maxing out that alternator.

i dont really think they need a lot cause theres not a whole lot to feed. thats why they came witha 75 amp or whatever. but the problem is, you end up overworking the alternator and having to replace it, thats why they suck.

Joel5.0

1) Yes on the amps max output, No on the rest.....voltage drops down when the amp requirements are increased. If you have 14.7-vdc showing on the voltmeter, amp output is low (not required so the regulator will do its job). When you turn all the accesories on (A/C, headlights, wipers, stop lights, reverse light, rear defroster......)....voltage output will drop as an indication amps requirements are high.

2) Again, Yes and No....amps required by the starter are while it is cranking, and it's defined by the condition of the engine and the starter motor itself....once you start the engine, no voltage/amps are applied to the starter....they get stored in the battery to resupply what was used by the starter, and reuse when needed. FYI...starters usually require an initial spike over 400A and ~200A to keep on cranking (if it doesn't start) as shown here....

So...if you have a high voltage reading at the battery, less current is being consumed....the lower the voltage, the higher the current the alternator is putting out.... Hope this helps.

silver91gt

the factory wiring isnt made to handle more amps, it has 2 little 10 gauge wires, if you are upgrading your alternator to a higher amp one, like a 3G alt, upgrade the wiring, all you need is a 4 gauge cable to go from the alt to the battery/solenoid

Dearborn5.0

thank you guys

my fear is that the vehicle will discharge itself when I run it at idle for long peroids of time.

I dont have a big system.

will the stock 2G support the vehicle power loads with extended idle?

I get 14.7 V at idle