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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: ITSANSS on June 26, 2010, 08:18:12 am

Title: One or Three Wire Alternator?
Post by: ITSANSS on June 26, 2010, 08:18:12 am
1985 Chevrolet Silverado
350c.i.
TH700R4

Do these pick-ups have a one wire or three wire alternator?  Gonna' order a chrome, 110A and want to be sure I get the right one.  Also, if I remember correctly, one wire has the two wire plug that goes into the alternator and to the back of the alternator?  I think that's what this pick-up has, but not for sure.  While we're on the subject, what amperage alternator did these pick-ups come with from the factory?  80A or somethin'?

Thanks!
Title: Re: One or Three Wire Alternator?
Post by: Irish_Alley on June 26, 2010, 09:04:27 am
Your truck should come with a one wire but like you said one wire has 3 wires the trucks came with about. 80 amp.
Title: Re: One or Three Wire Alternator?
Post by: DnStClr on June 26, 2010, 10:50:42 am
Here's kind of an interesting article about the advantages of a 3 wire alternator.

http://www.madelectrical.com/electricaltech/onewire-threewire.shtml
Title: Re: One or Three Wire Alternator?
Post by: Irish_Alley on June 26, 2010, 06:25:17 pm
What the heck was that lol they are trying to sell something so its going to be one sided but most of it is right. But nothing is wrong with a one wire, and if you need a dummy light then so be it but if you don't look at your gauges every now and then then how do you know how fast your going and let's say the water pump breaks or you sprung a leak then guess that dummy light won't save you. I would stick to the one wire even with high beams on wipers on and a radio will you see you volts drop less than .5 and a good alt thats about 13.8
Title: Re: One or Three Wire Alternator?
Post by: Irish_Alley on June 26, 2010, 07:02:42 pm
Also I never had to rev my engine to get the reg to kick in even at low rpms 700 its still at 14v
Title: Re: One or Three Wire Alternator?
Post by: VileZambonie on June 26, 2010, 10:33:47 pm
All SI Alternators were 3 wire. Isolated circuits are always better. One wire alternators are fine for hot rods but not for daily drivers imo.
Title: Re: One or Three Wire Alternator?
Post by: ITSANSS on July 02, 2010, 10:07:57 pm
Ok, let me rephrase this...   :)

Will this alternator work?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=110554657740&viewitem=&_trkparms=algo%3DLVI%26its%3DI%26otn%3D1&category=33573

Thanks!
Title: Re: One or Three Wire Alternator?
Post by: Irish_Alley on July 02, 2010, 11:56:50 pm
Should work just fine do a visual check and make sure everything is the same between yours and the picture before buying it ex. plugs on the right side pulleys are the same
Title: Re: One or Three Wire Alternator?
Post by: VileZambonie on July 03, 2010, 08:25:32 am
Will it work? Yes. Do you want a one wire is the question you need to ask yourself. Most people who run a one wire do it just to have a clean engine compartment with less wiring. It's not the most ideal system for a daily driver. Now you need to decide if it will work for you.
Title: Re: One or Three Wire Alternator?
Post by: beastie_3 on July 03, 2010, 09:42:53 am
I would at least spend a few more dollars and get one from Jegs or Summit. That way you know you wont have any issues with shipping or returns.
Title: Re: One or Three Wire Alternator?
Post by: Psycho71 on July 04, 2010, 01:56:32 am
I have one of those same alternators on my '71 C10. I had to chase the threads before I could thread a bolt into them, the ears aren't dimensionally correct, so i had to do some spacing on my brackets to get everything to line up.

But it works like a champ. Sits right on 14V all the time, well until I turn on the brights, crank the a/c wide open, and crank up the stereo, then it drops to the high to mid 13's when the bass hits. Mine's a 100amp model, btw.

I went one wire on this truck for simplicity sake, since I was re-wiring the whole truck anyway. And, like said above, it keeps the clutter down in the engine bay.

For the money, it's not a bad deal. But there very well could be minor issues like I experienced.