one wire alternator

i was reading somewhere that on one wire alternators (GM) that u dont use the top 2 prong plug, u only use the hot terminal on the back of the alternator and also use a volt meter with this set up......

is this true? if so im hooked up all wrong

 

more of the same

 

ONLY if its designed as a one wire....if so the plug is wired internally so you dont see it or have to hook up as above.

 

Whether you use a voltmeter or an ammeter has no bearing on how the alternator is hooked up. If your current system is working, there is no advantage to change it to a one wire system.

Is your wiring new? Did it work before?

 

Don't wire your car this way. The voltmeter needs to be on the "switched" side of the ignition switch. The way it's shown here, the voltmeter will always be on, and while it would take a while, is a parasitic drain that will eventually cause your battery to go dead.

 

The advantage to the ONE WIRE is that they are simple to hook up.

The disadvantage is you loose both the "warning light" and remote votage sensing.

If you have very little electrical load in a small car, the one wire is fine.

But if you have a larger car with long runs of wire and lots of electrical goodies hooked to a junction terminal, youre much better off with the three wire.

By hooking the sensing wire to the junction terminal, you maintain 12v THERE... not just at the back of the alternator.

Having 12v at the back of the alternator only will result in poor electrical performance, dim lights, etc....

 

with a 1 wire alt set up you have a parasitic draw so if leaving car sit for a long time use a battry disconnect

 

I agree 100%, and opening the link below will answer many questions about the popular GM 10SI/12SI alternators, and why one-wire isn't the best way to wire an alternator. Mark Hamilton has put together a wealth of info on the subject.

http://www.madelectrical.com/electrical-tech.shtml

 

well i have the two wire plug on top and the power on the back of the alternator,,,but i let my car sit for two days without starting and after 4 trys of starting it the battery went dead....this is a brand new battery and the alternator has been checked

thats why i thought maybe i had it hooked up wrong

its draining battery somewhere ,,,not sure where!!!!!

 

You need to find out what the problem is before you start throwing parts at it.