Do I need a Higher Amperage Alternator

[abbey castro]

I am currently running dual Sebring fans. I'm afraid that when I run the AC in high my alternator a 78amp AC Delco will not be able to keep up with the draw. Then if I drive at night with lights on, will it really draw further down and leave me stranded. I haven't driven at night lately so not sure I have a problem. Any actual experiences in this? I know recommendations "Go Higher Amp". Should I upgrade to 90-100 amp

 

[Wageslave]

Honestly, your alternator is probably fine. Those Sebring fans have a 25 amp startup current but only pull 12-13 amps once they are up to speed. I have ran them with a 63 amp alternator without issue (not including A/C). 78 amps should be plenty to run the A/C, fans, and other accessories together.

 

[kornball426]

Good to know info, I was worried about the amp and sub drawing too much power from my El Camino because it seems like the gauge runs lower than it did before.

 

[fleming442]

Amplifiers are much different than electric fans in terms of current draw. Like Wageslave said, there is a start up draw on electric fans, then they level out. Amplifiers are a wild card. How big? Regulated or unregulated? Is it wide open most of the time?

It's never a bad idea to upgrade your electron capacity.

 

[olds307 and 403]

I found the 78 amp alternator inadequate with underdrive pulleys with the lights turned on, blinker, blower fan, radio and cooling fans on. Don't these cooling fans draw 40+ amps at start up? I have blown quite a few 40 amp relays with the Stratus fans.

 

[Pc3]

I am currently running dual Sebring fans. I'm afraid that when I run the AC in high my alternator a 78amp AC Delco will not be able to keep up with the draw. Then if I drive at night with lights on, will it really draw further down and leave me stranded. I haven't driven at night lately so not sure I have a problem. Any actual experiences in this? I know recommendations "Go Higher Amp". Should I upgrade to 90-100 amp

Yes....
And get a excellent reading gauge.
I take it you pay attention when you drive.
That's a lot of amps drawing..
Relays help

 

[Rt Jam]

Get a fan controller with soft start but I agree, 78 amps is not enough.

Anything OEM with electric fans is over 100. Ratings aside, you will have max amp draw at idle and the 78 amp rating is not at idle.

 

[pontiacgp]

If your current set up is causing you concern an alternator upgrade is easy and relatively inexpensive so why not do it instead pf worrying about it. I would not buy an alternator from a retail parts store, I buy mine from a local rebuilder. You can easily upgrade to a CS130 which is a 105 amp.

 

[64nailhead]

For sure your 78amp alternator will keep up when every part of the charging system is up to snuff. The issue develops when something isn't. That is when being on the edge of the ratings is painful.

Put in a CS130 or 144 and never look back. I have a CS130 running two fans, two fuel pumps and two ecu with multiport injection and meth injection pump. It will lose .5-.7 volts at the end of a 1/4 mile pass - no big deal.

 

[pontiacgp]

For sure your 78amp alternator will keep up when every part of the charging system is up to snuff. The issue develops when something isn't. That is when being on the edge of the ratings is painful.

Put in a CS130 or 144 and never look back. I have a CS130 running two fans, two fuel pumps and two ecu with multiport injection and meth injection pump. It will lose .5-.7 volts at the end of a 1/4 mile pass - no big deal.

I have the 144, it is a large case alternator that puts out 140 amps while the CS130 is a small case which is the size of the stock alternators. The 144 mounts the same as the stock alternator