Stock Alternator Isnt Gonna Cut It

[gpracer1]

Truck is bone stock, stock radio.
With 110 degrees right now, it will still be 100 at 9pm. At a stoplight with the front and rear AC on high, with headlights on, in drive stopped with your foot on the brake = 11.95 volts !!

That means no Efan with the stock alternator, or 4 high mod either.

If I put it in neutral like this, and rev it, it is putting out 83 amps, idle = 60. Damn near the rated 100. I cant imagine it lasting all summer.

Ended up ordering a 220 amp alternator today since I will be pulling another 30ish amps more with an Efan setup.

On my 93 I got a smaller pulley, but that was barely enough.
What are you guys doing?

 

[HankHill]

Stock KG9 amp here.....140amps should be good

 

[taylorjm]

What's the 4 high mod? I tried searching, but you know how it hates when you try and search for things that are less than 4 letters long, so my search comes up with just "high"....

Ohhh, it has to do with lights...I thought it had to do with 4hi in the 4wd system...duh...thought I missed something!!

 

[gpracer1]

Stock KG9 amp here.....140amps should be good

Which trucks came with that?

---------- Post added at 06:50 PM ---------- Previous post was at 06:40 PM ----------

What's the 4 high mod? I tried searching, but you know how it hates when you try and search for things that are less than 4 letters long, so my search comes up with just "high"....

Ohhh, it has to do with lights...I thought it had to do with 4hi in the 4wd system...duh...thought I missed something!!

High beams are about 10 amps.

Low beams with running lights are 15 amps.
Both would be 25. It would max out the alternator which Im sure makes it runs hot as hell and reduces its life. Went through 4 or 5 alternators in my 93 with electric fans and 4 high mod till I put in an Iceberg alternator high output kit.

 

[HankHill]

Mine is a 2000 OBS Tahoe...prolly the heated seats drove the ** alt...

 

[SunlitComet]

Planning on a Powermaster cs144 style 200 amp myself later on with a smaller pulley if possible and an correctly sized belt to ensure proper tension. I want to have a second battery bank and more electrical components in first. Should be able to cover my current setup with air compressor, lights, efans and some other goodies later on.

 

[sparg93]

For efans, like you mentioned...the stock 105 isn't going to cut it....the Mark VIII is a beast and pulls a ton of power.

I have a 140amp (GM **) and I can tell with my 4high mod, 1500w subs and Mark VIII it's getting close!! I'm wiring in my 130w offroad lights this summer, so we shall see if that's the last big electric add for me!

 

[gpracer1]

For efans, like you mentioned...the stock 105 isn't going to cut it....the Mark VIII is a beast and pulls a ton of power.

I have a 140amp (GM **) and I can tell with my 4high mod, 1500w subs and Mark VIII it's getting close!! I'm wiring in my 130w offroad lights this summer, so we shall see if that's the last big electric add for me!

How is your Mark 8 setup, setup?

 

[gpracer1]

Well, it was 112 F today. I get home and the new 220 amp alternator is sitting by the front door.

I unpack it, check it out and decide to put it on.......oh, whats that on the ground? A puddle of coolant?

Freakin 2 inch crack under the upper hose down past the oil cooler inlet.

So now Im off to Autozone to pick up a radiator, coolant, and a shorter belt since I noticed the pulley is smaller. Guess thats why it puts out way more at idle than stock. Alternator is goin on after that.

 

[gpracer1]

220 amp alternator is worse than stock at idle. And it has a 1 7/8 " small ass pulley on it!!
I swapped the pulley with my stock alt and it works way better at idle than before.

Have to send the new alt back. Emailed the guy and he said they are no good for idle, just for making big power while driving or at 1200 rpms or over.

So instead I got a used 140 amp stock alt for $50 and ordered a 1 7/8" pulley for that since I plan on efans. The whole "220" amp didnt turn out quite as I expected.