Alternator Qustions

[dslksl]

I have a 2003 Yukon XL with a 5.3 and a 145 amp alternator, and I have a 2004 Sierra with 4.3 and a 105 amp alternator.

 

1. Can some tell me what amp these put out at idle?

2. Can I switch them?

 

Thanks,

[bobcat5544]

Yes. You can switch the two alt.

Far as what the amperage is at idle, it will differ from truck to truck. ballpark i would say about 35-50 amps at idle.

[dslksl]

Thanks,

 

Is there any good way I can check the amp out put?

I have a Fluke clamp on amp meter.

[GM-Tech]

There is no spec on amperage output at idle. The alternator will be putting out whatever is necessary so you have no basis for comparison. For instance, if you have one with a somewhat discharged battery and one with a fully charged battery, they're both going to read something different at idle. Which one is right? Probably both of them. Yes, you may have one that's putting out 30-50 amps at idle, but you could have one that's nearly zero. Neither would necessarily be wrong.

 

The proper way to test an alternator is through a load test. Basically, connect a carbon pile to the battery, run the engine at 2000, all electrical components OFF and load the battery to the amount specified in a load test chart we have. If it is able to reach that spec, it's output is good.

[drumset5994]

I read about this...where the Alternator only maintains the charge to the battery while everything electrical is running (including PCM) and things like that.

 

Most likely why my brother (idiot) blew through 3 alternators in a week...kept starting his truck with a dead battery and let it "charge" .

[Wingnut]

I read about this...where the Alternator only maintains the charge to the battery while everything electrical is running (including PCM) and things like that.

 

Most likely why my brother (idiot) blew through 3 alternators in a week...kept starting his truck with a dead battery and let it "charge" .

 

<{POST_SNAPBACK}>

 

 

 

 

When I was 16-17, I drove on alternator power only for a week solid.

 

But that was a '72 El Camino, and all I needed was a jumpstart. Motor would run fine without electrical. I also couldn't drive much at night

 

Boy...THAT payday (and a new battery) felt like it took a month to come around, instead of 5 or 6 days.