Not charging to well on idle with everything on

[Rob04Mach1]

I have 13.8 - 14.1 Volts on idle and when I put the AC on it drops down to 12.8 - 13.3 but still stays in the green. However if I put my 2nd Aux Radiator Fan on AND my Aux Transmission Fan on the volts drops way down to the 12's and the gauge goes into the red. But when I bring the revs to 1500 RPM it jumps immediately back to the green and back up to 13.8 - 14.1 volts
(it still may be a little weak from yesterday when I got stuck with a dead batt)

I'm glad I had this Digital Amp Gauge that plugs in the Cig Lighter with the Green Yellow and Red Lights because now I see whats going on and where I went wrong yesterday and why I got caught out there.

I went to Long Island Lightning Fest II with @ 30 Lightnings and Me and a Friend with our Cobra's yesterday. It was great to see all my old friends and make some new ones, (5 States were represented)

Unfortunately it was EXTREMELY HOT, and dam near impossible trying to get 30 - 35 vehicles through the traffic lights (especially turn signals) and we spend hours in traffic. We met out in suffolk and then drove to SR mall for some pictures, and then somewhere else, and then somewhere else, and and and finally to the nautical mile in freeport. IT WAS F-ING PACKED

A lot of people were running hotter than normal me included so I had the Aux Rad Fan on and my Aux Transmission Fan on and my normal Radiator Fan on and Max AC and the Music was cranking. We were idled for a long time and I shut it down for like the hundredth time of the day and that one time the batt was too weak to restart it (took a jump no problem though).

I shut the AC and both Aux Fans and drove 2 blocks and shut it down and it was fine after that. Started no prob last night for the ride home and started a few times today no prob so it is charging and all is fine.

Obviously the car didnt come with all these extra fans but I was told I had a
180 Amp Alternator so my question is this...
Does it make sense that with EVERYTHING ON and "3" Electric Fans going I wouldnt be charging at say 1000 RPM but would be at 1500 RPM ???
Maybe like you got to spin that Alt a little to get it going ??? or am I looking at my Alt slowly going bad ??? Or are those Extra 2 Aux Fans just to much for the system ??? (up to this point I have only switched them on a few times and right off after a few minutes, yesterday I ran them both for hours and hours...)

I'll use the Amp Gauge a while and watch it but just wanted to get some opinions and input from others that may be running extra Fans...

 

[Wicked One]

From how you describe it, it sounds perfectly normal for the draw not to be able to be recouped at the 1K rpm.

This is known also to happen when UDP are used, the alternator speed is not enough to charge.

If you are getting 14v at idle you are charging.

No worries man, with all the current that your fans and other acc. are drawing, you are good to go if it is charging at 1500.

 

[88slowmarro]

i agree . thats why u/d pullies make power they dog everything off

 

[Rob04Mach1]

Thats what I was thinking Thanks Guys

When I jumped it and drove it two blocks and it started on it's own later (and with no problems yesterday) I kind of assumed it was nothing to worry about.

Sat was one of the hottest most extreme days I'll prob ever drive in. With all the stop and go traffic we sat in, all the restarts, all the idling time, and then me leaving those two Aux Fans running for hours on end (for the first time),
on top of Max AC and the Radio, I now know thats simply too much for the Charging System if I'm sitting there idling at 1000 RPM for long periods of time.

For now on in I'll do what I was doing and only use those extra fans if I'm moving and if I really need them

 

[ShelbyGT]

sounds like you really put it through its paces yesterday. i'd say its ok. if i was you, when you run the aux. fans for a while just hold it up to 1500rpm so it charges

 

[ShelbyGT]

but, your alt may be alittle weak, an alt should not require an rpm increase to produce max. charging. old generator style charging systems did require above an idle to charge well but mordern alternators should not

 

[BlackOut2k11]

but, your alt may be alittle weak, an alt should not require an rpm increase to produce max. charging. old generator style charging systems did require above an idle to charge well but mordern alternators should not

This is not true. An alternator will never produce its full capable output at idle RPM. It will usually produce about 50% of it's max at idle, so a stock 130 amp unit will produce ~65 amps at idle, where say a beefed up 200 amp will produce 100 or more at idle. The idle amperage goes down when you use underdrive pullies, hence why I hate them, makes things a nightmare for people like me.

If you're losing voltage at idle it means the alternator is putting out full capacity at that RPM and is unable to keep up with the load, so you're only options are to either reduce load or go with a heavier duty alternator that can handle the electrical load.

 

[ShelbyGT]

This is not true. An alternator will never produce its full capable output at idle RPM. It will usually produce about 50% of it's max at idle, so a stock 130 amp unit will produce ~65 amps at idle, where say a beefed up 200 amp will produce 100 or more at idle. The idle amperage goes down when you use underdrive pullies, hence why I hate them, makes things a nightmare for people like me.

If you're losing voltage at idle it means the alternator is putting out full capacity at that RPM and is unable to keep up with the load, so you're only options are to either reduce load or go with a heavier duty alternator that can handle the electrical load.

ok, guess i was wrong. i was always told that but ok:smash: