alt at car start up

[bri487 5,000+ posts]

i know, its once i start moving a little too, idk what it is, thats why im trying to solve this problem. do you think it could be that its breaking that max out put phase?

dont roll down your windows and turn off the ac/heater and all other electronics in the car, then test out your theory again.

 

[wilzyx 5,000+ posts]

so what exactly is your problem? your getting 14.8 volts at idle and 14.3 while driving, thats pretty good.

 

[bri487 5,000+ posts]

so what exactly is your problem? your getting 14.8 volts at idle and 14.3 while driving, thats pretty good.

he should be making more while driving than at idle.

 

[photocrazy8 10+ year member]

so what exactly is your problem? your getting 14.8 volts at idle and 14.3 while driving, thats pretty good.

this is only while i get the random spurts of max out put at idle b4 i move my car. i have a bad voltage drop problem that in trying to fix...

 

[photocrazy8 10+ year member]

dont roll down your windows and turn off the ac/heater and all other electronics in the car, then test out your theory again.

so what do you want me to do exactly?

 

[RandyJ 10+ year member]

i know, its once i start moving a little too, idk what it is, thats why im trying to solve this problem. do you think it could be that its breaking that max out put phase?

What I'm telling you is that an alternator is a device whose output is directly (in this case) related to the engines speed. Thus, if you are in Park and getting "full" output, but lose it once you shift into drive, then there are some appliances that kick in and start to draw power once you do so.

Like I said once before,

Try shifting out of park and inrto nuetral, then turn the motor over to about 2,000-2,200 RPM's and see what your voltage does.

 

[photocrazy8 10+ year member]

ok, i did what you said and the voltage stays the same around 14.x range and then once it come down from the 2000 + range it stays at 14.x with the system off. i also tried it with the system on at full tilt and at the 2000+ range i got about 13.8-14.1 and then when the RPM's dropped the voltage dropped to 12.4 range.

I agree with you that the alt output is based off of RPM's, but the question im trying to get at is...those times when i get it to hold at 14.1+ at idle with the system at full tilt,... is that one of those max out put times or is it just the alt doing normal out put and the rest of the times i have a voltage drop because the alt is having a mechanical fault.

because i think that 180 amp draw for just a JL 1000/1 is sorta high, and i figure my car needs about 40 amps to run (stock stuff). thanks, andrew