GW56, what is the output (amps) of the alternator and type, 10SI, 12SI or other. Also, where is it mounted, high or low as overheating the alternator will ultimately burn it up. The 12SI cools internally better than the 10SI. I know I had two 10SI, at 120amps quit on me so I went with the 12SI and solved that problem. I also ran a larger wire #8 from the alternator output.

Joe,

 

Joe, I am not sure if it is a 10SI or 12SI. They tell me it is a 63 amp. upper mount with short water pump.
Is there a way to tell if it is 10SI or 12SI?
It has a large wire...unsure of the gage since i did not install it myself.

Thanks for the reply.
3:

 

Now the alternator (1 wire) runs to the starter.

Is it a 1 wire alternator? Most parts store alternators are 3 wire and require the "gen" light to be connected. Is the "gen" ight on? With a 3 wire alternator, if the "gen" bulb is burned out, the alternator won't be excited enough to charge.

 

It is a 1 wire alternator.

thanks for the reply though

:bowtieb:

 

I just checked with O'Reilly (where I bought the last two alternators) and the alternator I got is for the correct engine, but they are saying it puts out 63 amps and 12 volts. Is this the correct alternator? I asked if it was 10SI or 12SI and they have no idea what I am talking about. Can anyone clarify what the correct alternator is for a 1974 SS 454 4 bolt main?

:gba:

 

The alternator doesn't have to match the engine. If your getting a OEM alternator that fits a 74 SS, it IS NOT a 1 wire alternator. To my knowledge GM never used a 1 wire alternator on production cars. OEM type alternators need a excitor and voltage sense wire connected to the small plug to perform correctly. Check this site for the difference between a 10 and 12 SI, but if you have a 3 wire alternator that isn't wired completely, it will overcharge and ruin a battery, IF it ever starts charging. .... http://www.madelectrical.com/electricaltech/delcoremy.shtml
The 12SI wasn't made until 1983.

 

A 63 amp delco is probably a 10si. A picture would help.

Untill you can get under it and check for loose connections, I don't think we can help you.

A 1 wire is a no brainer. just a wire to the battery. If the wire is connection and the alternator is good and is turning it should charge.

You can run a second 12 ga wire from the bat termainal to the battery to test your theory.

I know you said you don;t want to change to a 3 wire, but a 1 wire is not as good a setup.

 

I will post a pic.
I spent hours under it on sunday and found a loose connection at the battery kill switch - installed under the seat, but I tightened it up and still not getting over 11.5 to 12 volts from the battery or the alternator I need to run a straight wire to the alternator or pull the alternator and have it bench tested...it could be the problem itself.
I will update again once i know more.

Thank you for your help everyone. It gets me motivated to get under there and figure this stuff out.
You guys rock
:flag6:

 

I had basically the same problem; several new alternators quit working, to include 160 amps etc.

Finally I figured out while running the big block put out so much heat and the regulator, built into the alternator, would overheat and stop working.

So the answer was to get an alternator with dual fans, one internal and one external, And that the regulator instead of inside the alternator likes most are, the regulator was mounted to the rear of the alternator.

Solved the problem, Nascar also runs the dual fan type alternator for the same reason.


The alternator type is a cs130

otis

 

Thanks Otis this could be my answer. Although, i know there is something up with the wiring or the alternator is just no good. That sounds like a really good upgrade.

 

I had the same problem and change 3 alt. before I install a duel fan alt. and that fix it.

 

I agree with the guys, if my alternator goes out again I'll be going to a CS-130. Lots of cooling and output power. My 12-SI at 120 amps seems to be marginal with what all i need to power, dual fans, vintage air, redline head lights, 900 watt amp, etc.

Joe,

 

Summit Racing sells all kinds of One-Wire self exciting internally regulated alternators. Or if you have a shop in town that deals only with batteries and charging systems that would be another good place to check... In the town I live in there is a United Battery and the guys there know way more then anyone at Shucks O'Rielys. I have wired up the three wire alternators from scratch on a few old dump trucks and it is not too tough. Luckily there is just as many options and prices to fit your exact needs.

 

Rob, I should have just bought one like you suggested from Summit, but O'reilly will not give me the money back only let me exchange.....so here i am in the same situation again and paid another 60+ for this 105 amp that doesn't work.

 

okay, first off I just want to say thanks for all the help from all you trifive lovers.

So, no i went and exchanged the aternator for one I thought would work. It is this alternator http://www.oreillyauto.com/site/c/detail/ULT0/010244.oap?ck=Search_01-0244_-1_2889&keyword=01-0244

It still is not charging. I am not sure if this is a ligitimite one wire alternator. I know it is not charging though. I have the one wire hooked up, it has nothing connected to a indicator light, just the one wire straight to the battery. The guy at the store seemed to think it would work, but still not working. I have no fuse attached, but from the limited info I know I should be able to run the one wire straight to the battery and it should charge....right?

Anyone have any advise how I can get this altrnator to work? I have a ton of wire, but no indicator light.

My only other suggestion would be I can take the fan and pulley off this one and go back to my original 80 amp one that shot the fan blade into my hood. Is that a better solution? Please help......driving me freaking nuts....

I am now on the 3rd alternator that has not worked.

 

That's not a one wire alternator either. A one wire alternator will "usually" have a plastic cover over the small 2 terminal connector. Do you have Autozone? .... http://www.autozone.com/autozone/accessories/Proform-80-Amps-one-wire-chrome-machined-pulley-alternator-for-GM/_/N-2695?itemIdentifier=523738_0_0_ or you could go to Summit, Jegs, Speedway Motors, or any hot rod supplier for a one wire alternator.
You can see the 2 terminals on the left, in this picture of the Ultima. A one wire "should" have them covered.

 

GW, you may have mentioned it, but I don't remember, do you have the original type wiring where the wires from the original generator may still be taped up in the harness? You could very easily wire the alternator for 3 wire and solve the problem if you want.

 

I looked and I cannot see the original wiring.
I will see if Oreilly will order me one of the 1 wire alternators like you suggested.

 

I agree with acardon, by now you could have had the thing wired up 3 wire and had a indicatior light too.

 

it does not have the original wiring, but thanks for your input.

 

got my money back and used your guys advice and got a real one wire from Jegs. Should be here today!

here it is http://www.jegs.com/i/JEGS+Performance+Products/555/10120/10002/-1
i'm pretty sure this will solve my problems and I saved 60 bucks.

Thanks guys i will install tonight or tomorrow....

 

not sure if anyone really cares, but got the correct one wire alternator and installed it.....finally working......14.5 volts.......so happy.

Car runs great and back on the road

thanks for all the help and comments

:tu

:gba:

 

not sure if anyone really cares,

Car runs great and back on the road

We care. :tu :tu :tu