Question on Alt. I Need HELP - The 1947 - Present Chevrolet & GMC Truck Message Board Network

SEVEND2 · 11-12-2003, 04:07 PM

Where does the Ground Wire go? I have a terminal on the back of the alt. for Ground and dont have a Gound wire to hook up.

Does anyone have a Ground if so where does it go.

Mine has 3 wires, 2 to the clip plug in and 1 that goes to a thread connector

also

How hot does a Alt get?? I can barely touch mine bare handed after running 5 min
Also

When I idel it is a hair above center on needle on the meter, when i rev or give it gas, it goes up , and when i get on it It goes to Full charge on the gauge.

Any input on that?

Thanks

Slammed67 · 11-12-2003, 04:25 PM

Ground wire???? Is this an internally regulated alternator? If so, it shouldn't have a ground wire. There should be a wire going from the post on (back terminal) to the battery. Then a wire going from the post to the large wire on the connector. The smaller wire goes to a switched 12v source. This is how mine is wired up anyway.

I don't recall how the externally regulated ones are wired up

SEVEND2 · 11-12-2003, 04:49 PM

It says GND, on the Alt. Back side. I dont have a Wire for it, I was just wondering it I should have.

pbmcauliffe · 11-12-2003, 05:45 PM

Most of the time the ground is carried via the mounting of the alternator to the engine, but some times they don't ground well (powder coated cases, chrome, etc.) so you can run a cable from the gnd terminal to the engine block, frame, etc. to better the grounding.

zyggy72 · 11-12-2003, 06:17 PM

What year truck? If it is your 72 and is the original setup then, you also have a voltage regulator and if I remember correctly, the ground wire goes from the back of the alt. to the voltage regulator or something of that nature.
If only I had the factory assembly manual in front of me, I could tell you for sure.

SEVEND2 · 11-12-2003, 06:54 PM

Got it for the ground Question

Ok, should the Alt. be getting hot (almost to hot to touch) after 5 min- 10 min?

and anyone else having Volt meter changes when the RPM's go up?

Longhorn Man · 11-13-2003, 01:04 AM

Your volts may go up a little when you rev it...or more acurately drop at idle...but if it goes much past 14 volts, you have a problem.

SEVEND2 · 11-13-2003, 01:14 AM

well at idle I am about center on the meter, any increase of RPM increases the needle to more charging, When i am driving its is pegged past Full max charging.

Might have to take it out and go exchange it again

Longhorn Man · 11-13-2003, 01:39 AM

You talking volt meter...or the stock amp guage?
If you are going by a stock guage, put a hand helpd multimeter on there and see what's actually going on.

SEVEND2 · 11-13-2003, 02:32 AM

yeah I am just going off the In dash Meter.....

The Wires nor the Batt. is warm or Hot, just the casing of the Alt is Very warm, enough to pull your had away at first touch (i never really noticed that before).. But, thanks for the idea on the Multi Volt meter on the connectors......

What points should i test? Across Batt terminals, other points??

Longhorn Man · 11-14-2003, 12:50 AM

Battery is fine. Make sure to rev it up when you test the voltage too.
I've never heard of a set up (working properly) that will move the needle that much when you rev it up.

SEVEND2 · 11-14-2003, 06:51 PM

OK, found this..........

Alt. Was good, not causing the problem...

It was the External Volt reg. I guess and the guess of a few local Auto shops that the Other Alt. Went out it shorted out or damaged the Volt Regulator.

So.

I replaced the regulator with a new one

And BAM.. It works Great again, max charge was 13.6V
Running at various rmp's at 12.4 average

Just an FYI. If anyone else has this problem, Check the Regulator!!

And thanks Members for your help

11-12-2003, 04:07 PM	#1
SEVEND2 Registered User Join Date: Aug 2001 Location: Menifee, Calif, USA Posts: 2,145	Question on Alt. I Need HELP Where does the Ground Wire go? I have a terminal on the back of the alt. for Ground and dont have a Gound wire to hook up. Does anyone have a Ground if so where does it go. Mine has 3 wires, 2 to the clip plug in and 1 that goes to a thread connector also How hot does a Alt get?? I can barely touch mine bare handed after running 5 min Also When I idel it is a hair above center on needle on the meter, when i rev or give it gas, it goes up , and when i get on it It goes to Full charge on the gauge. Any input on that? Thanks __________________ With a 1972 Chevy Custom-10 Long bed w/350cid th350, (under-construction). Progress on truck so far (follow link): http://67-72chevytrucks.com/vboard/s...ad.php?t=51051 and stage 2 http://67-72chevytrucks.com/vboard/s...ad.php?t=58132 ~ "Why couldn't you have just put the bunny back in the box?" ~

11-12-2003, 04:25 PM	#2
Slammed67 Progress = 0% Join Date: Nov 2001 Location: Kansas City, MO Posts: 2,108	Ground wire???? Is this an internally regulated alternator? If so, it shouldn't have a ground wire. There should be a wire going from the post on (back terminal) to the battery. Then a wire going from the post to the large wire on the connector. The smaller wire goes to a switched 12v source. This is how mine is wired up anyway. I don't recall how the externally regulated ones are wired up __________________ Jason - '67 GMC swb \| '57 Bel-Air 4dr hardtop \| '56 210 4dr Wagon \| 2000 GMC Sierra

11-12-2003, 04:49 PM	#3
SEVEND2 Registered User Join Date: Aug 2001 Location: Menifee, Calif, USA Posts: 2,145	It says GND, on the Alt. Back side. I dont have a Wire for it, I was just wondering it I should have. __________________ With a 1972 Chevy Custom-10 Long bed w/350cid th350, (under-construction). Progress on truck so far (follow link): http://67-72chevytrucks.com/vboard/s...ad.php?t=51051 and stage 2 http://67-72chevytrucks.com/vboard/s...ad.php?t=58132 ~ "Why couldn't you have just put the bunny back in the box?" ~

11-12-2003, 06:54 PM	#6
SEVEND2 Registered User Join Date: Aug 2001 Location: Menifee, Calif, USA Posts: 2,145	Got it for the ground Question Ok, should the Alt. be getting hot (almost to hot to touch) after 5 min- 10 min? and anyone else having Volt meter changes when the RPM's go up? __________________ With a 1972 Chevy Custom-10 Long bed w/350cid th350, (under-construction). Progress on truck so far (follow link): http://67-72chevytrucks.com/vboard/s...ad.php?t=51051 and stage 2 http://67-72chevytrucks.com/vboard/s...ad.php?t=58132 ~ "Why couldn't you have just put the bunny back in the box?" ~

11-13-2003, 01:14 AM	#8
SEVEND2 Registered User Join Date: Aug 2001 Location: Menifee, Calif, USA Posts: 2,145	well at idle I am about center on the meter, any increase of RPM increases the needle to more charging, When i am driving its is pegged past Full max charging. Might have to take it out and go exchange it again __________________ With a 1972 Chevy Custom-10 Long bed w/350cid th350, (under-construction). Progress on truck so far (follow link): http://67-72chevytrucks.com/vboard/s...ad.php?t=51051 and stage 2 http://67-72chevytrucks.com/vboard/s...ad.php?t=58132 ~ "Why couldn't you have just put the bunny back in the box?" ~

11-12-2003, 05:45 PM	#4
pbmcauliffe Registered User Join Date: Nov 2003 Location: Bremerton, WA. Posts: 104	Most of the time the ground is carried via the mounting of the alternator to the engine, but some times they don't ground well (powder coated cases, chrome, etc.) so you can run a cable from the gnd terminal to the engine block, frame, etc. to better the grounding.

11-12-2003, 06:17 PM	#5
zyggy72 Can't kick the addiction! Join Date: Jan 2002 Location: Riverton, CT 06065 Posts: 402	What year truck? If it is your 72 and is the original setup then, you also have a voltage regulator and if I remember correctly, the ground wire goes from the back of the alt. to the voltage regulator or something of that nature. If only I had the factory assembly manual in front of me, I could tell you for sure.

11-13-2003, 01:04 AM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Your volts may go up a little when you rev it...or more acurately drop at idle...but if it goes much past 14 volts, you have a problem.

11-13-2003, 01:39 AM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	You talking volt meter...or the stock amp guage? If you are going by a stock guage, put a hand helpd multimeter on there and see what's actually going on.

11-13-2003, 02:32 AM	#10
SEVEND2 Registered User Join Date: Aug 2001 Location: Menifee, Calif, USA Posts: 2,145	yeah I am just going off the In dash Meter..... The Wires nor the Batt. is warm or Hot, just the casing of the Alt is Very warm, enough to pull your had away at first touch (i never really noticed that before).. But, thanks for the idea on the Multi Volt meter on the connectors...... What points should i test? Across Batt terminals, other points?? __________________ With a 1972 Chevy Custom-10 Long bed w/350cid th350, (under-construction). Progress on truck so far (follow link): http://67-72chevytrucks.com/vboard/s...ad.php?t=51051 and stage 2 http://67-72chevytrucks.com/vboard/s...ad.php?t=58132 ~ "Why couldn't you have just put the bunny back in the box?" ~

11-14-2003, 12:50 AM	#11
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Battery is fine. Make sure to rev it up when you test the voltage too. I've never heard of a set up (working properly) that will move the needle that much when you rev it up.

11-14-2003, 06:51 PM	#12
SEVEND2 Registered User Join Date: Aug 2001 Location: Menifee, Calif, USA Posts: 2,145	OK, found this.......... Alt. Was good, not causing the problem... It was the External Volt reg. I guess and the guess of a few local Auto shops that the Other Alt. Went out it shorted out or damaged the Volt Regulator. So. I replaced the regulator with a new one And BAM.. It works Great again, max charge was 13.6V Running at various rmp's at 12.4 average Just an FYI. If anyone else has this problem, Check the Regulator!! And thanks Members for your help __________________ With a 1972 Chevy Custom-10 Long bed w/350cid th350, (under-construction). Progress on truck so far (follow link): http://67-72chevytrucks.com/vboard/s...ad.php?t=51051 and stage 2 http://67-72chevytrucks.com/vboard/s...ad.php?t=58132 ~ "Why couldn't you have just put the bunny back in the box?" ~



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