TAC Tech => Electrical => Topic started by: SoupMan on August 31, 2018, 11:06:09 PM

Title: Alternator and charge indicator
Post by: SoupMan on August 31, 2018, 11:06:09 PM
Hi,

The new power master alternator I'm planning on installing has a tech note saying that on 3 wire installation, a diode should be installed if the vehicle does not have a charge indicator.

My first question: in my 1980 Firebird, at the top of the speedometer, their appears to be a blue square that can light up. Is this a charge indicator?  I tried to shine a light but could not make up any symbols.

My next question is: If not, what is recommended in regards to installing a diode?  The reasoning appears to be that it would prevent damage to the voltage regulator inside the alternator.

Any advice is appreciated.
Title: Re: Alternator and charge indicator
Post by: firebirdparts on September 03, 2018, 04:50:15 AM
I've never heard of that installation being required, but I think you don't have a charge indicator and you want to just put the diode in where they say to, in the original factory wire.

The light at the top of the speedometer is high beams.
Title: Re: Alternator and charge indicator
Post by: Jack on September 03, 2018, 06:29:02 AM
Cars without rally gauges came with warning light, is this what you are planning to install? It's a good idea if you don't have a voltmeter otherwise you don't need it.
Title: Re: Alternator and charge indicator
Post by: SoupMan on September 03, 2018, 06:43:13 PM
Other than it gives you a clear visual that something is working/not working, there's something about voltage feedback into the alternator. I'm trying to find the article I read on my phone 2 days ago that explained that most modern alternators have internal protections but that those who don't can end up damaging their voltage regulator.

I'll wire a 194 in line as per manufacturer instructions just to be on the safe side.
Title: Re: Alternator and charge indicator
Post by: Jur5664 on September 07, 2018, 07:31:13 AM
at the top of the speedometer, their appears to be a blue square .

It is the light for high beam when they are on  :P
Title: Re: Alternator and charge indicator
Post by: Aus78Formula on September 07, 2018, 07:47:12 AM
 :lol:       so.....not a sign of battery drain when high-beams are on?!
Title: Re: Alternator and charge indicator
Post by: Jur5664 on September 09, 2018, 04:10:14 AM
:lol:       so.....not a sign of battery drain when high-beams are on?!

No
Title: Re: Alternator and charge indicator
Post by: Aus78Formula on September 09, 2018, 04:19:10 AM
not the place for rhetoric then
Title: Re: Alternator and charge indicator
Post by: mlewisariz on September 09, 2018, 10:24:15 AM
The note says if "not" using a charge indicator. I think a voltmeter, ammeter, or idiot light would qualify as charge indicators.
Title: Re: Alternator and charge indicator
Post by: hakitup on September 09, 2018, 11:36:24 AM
If I remember right the alternator exciter wire is keyed power that goes through the indicator and once the alt starts charging it makes both sides positive and the light goes out.

Tom H
Title: Re: Alternator and charge indicator
Post by: firebirdparts on September 09, 2018, 04:50:04 PM
The note says if "not" using a charge indicator. I think a voltmeter, ammeter, or idiot light would qualify as charge indicators.

That's not what they mean.
Title: Re: Alternator and charge indicator
Post by: mlewisariz on September 10, 2018, 10:39:19 AM
Well,my bad. What is a "charge indicator" and why do you need one?
Title: Re: Alternator and charge indicator
Post by: mlewisariz on September 13, 2018, 11:08:07 AM
firebirdparts, I wasn't being snarky, I was actually asking what & why about "charge indicator". Anyone have explanation?
Title: Re: Alternator and charge indicator
Post by: firebirdparts on September 14, 2018, 06:18:36 AM
They mean that 1 wire in a 3 wire alternator has a lamp in it.  That is a common type of charge indicator.  I never heard of this diode requirement, so I am not sure what the deal was, but it was totally an assumption on my part that they meant if there's not a lightbulb in this particular circuit, then you need to put this diode in that same wire.  I may be wrong about what they are saying.