Hooray for a 105amp internally regulated alternator!

[Can30Diesel]

Well I finally got time to try and figure out what was up with my battery and charging system. Seems my alternator packed it in. 11.5v at idle and no change regardless of RPM. So now I have this nice 105 amp alternator I picked up brand new. I did the same test.. 14.5v at idle with no electrical load on the truck. It went down to about 13.5v with everything turned on at idle.

I think I can live with this.

 

[icanfixall]

Yes you can live with that. Remember that all the alternater was designed for is refilling the batteries after an engine start and then running all the electrical items as you drive. If it were the other way and we lived off the battery we would get very far down the road. Now if the alternater ever goes bad shut down as much electrical as you can and still drive safely. All we need is around 6 or 7 volts to operate the injection pump fuel shutoff solenoid. And if we remove the chevk valve in the return side of the pump we can run till we use up all the fuel. But we can't shut down the engine unless we cut off the fuel or air to the engine.. This is something we don't usually talk about but here it is anyway..

 

[riotwarrior]

IIRC don't you have a GM (cough) Alternator on that puppy????

 

[Can30Diesel]

Well I also have an electric lift pump to power.

Yes Al I do have a gm alternator. I like the whole internally regulated thing.

 

[riotwarrior]

Well I also have an electric lift pump to power.

Yes Al I do have a gm alternator. I like the whole internally regulated thing.

Bahumbug, I'll stick wiith my 3G internally regulated alt once I've serp braketed out my ride!

That lil pump is about same draw as my little pump... = NOT much

Ya the chevy alt is an easy swap well worth while!

 

[swervyjoe]

I like the whole internally regulated thing.

Thats the reason I went 3G

 

[PackRat239]

Electric fuel pumps take a LOT more juice than you might expect, which is why you are supposed to wire them direct to the battery thru a fuse and relay. Otherwise they dont last long or work well.

 

[Can30Diesel]

Well my truck has actually lost the lathargicness it used to get near the end of the day. My pump is wired right to the batter via a constant duty heavy duty relay. Maybe a few years down the road I'll revamp the whole electrical system and with that move to another alternator, but the chev alternator seems to be doing the job, even if I had to ream out the bottom bolt hole by 1/8" to make it fit the stock bolt. Not having to put my truck on a battery charger every night is nice too. I had been doing that for about a week since I discovered my alternator died. It was an unknown used one from picky, so who knows what it went through before I got it. The one I have now has a 1 year free replacement if it dies for whatever reason, then for the next couple years after that if it dies, I get it rebuilt for free. Not bad for $135 taxes in.

 

[Can30Diesel]

Here is a pic of the alternator..

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And the lift pump..

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This is one of the many band-aids on the truck, its not intended to stay like this....

 

[icanfixall]

Thats a nice clean installation but I would have replaced the feed line all the way to the filter head. That brass nut has an olive seal in it and we know they harden and leak. Just install a barbed 90 fitting and a longer piece of rubber hose. That eliminates another possible leakey connection or two.

 

[dmaxjoe]

How did you wire that alternater?

 

[icanfixall]

I would never have thought a GM internally regulated alternater was going to fit our truck engines but it clearly does. I'm also interested in how it was wired. I'm guessing same as the one the serpentine belt alternater is wired.

 

[79jasper]

Yep. Most gm alts are two wire. Which IIRC, is just a ignition on wire.

 

[Can30Diesel]

Yup, this is a 2 wire GM alternator. the white wire goes to the idiot light (I just omitted that for now) the red one either goes to an ignition switchable 12v or in most cases people just tie it to the battery charge bolt on the back. the factory white plastic connector was loose, so I just replaced it with a blade connector. Then there is a 8ga wire that goes from the battery bolt on the back of the alternator to the battery. I swapped the pully with the 2 groove one on my old alternator and I had to hone out the bottom bolt hole about 1/8" and thats about it. It works well. No more worry about external regulators failing, harness short-outs and resulting fires, etc. My only problem is its too damned shiny!

 

[icanfixall]

Shinny is good. you know it will change in time too.