HELP! 86'Firebird 2.8 won't charge more than 12V

Page 1 of 2  
My Son swaped a bone yard 85 camaro 2.8v6 into an 86 Firebird. Runs great for about 10 20 miniutes, untill volts drop down, down down till she runs out of battery!
New Battery- New Alt (bench tested at 15V twice) Voltmeter on dash says it starts up at 12V. Battery checks the same 12V Big terminal on Alt check same 12V
All three points check the same readings, even as the volts start droping down to about 7-8 volts. As it goes down you have about 2minites to compair & check points till she's dead.
Charge Batt & away we go again for another 10-20 minites
Checked & cleaned as many ground wires were accessable. Big one on front of engine - back one by firewall - one big gouping connected to the back of the head we could not really get at, but we just put them on when installing the engine.
Checked terminals at starter R & S + big positive cable.
Got us stumped why the voltage reg wont kick in when on the vehicle. On the bench - no problem!
Where to look now?
Thanks in advance! Gil
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

If you check your output with a digital meter, what do you get? Your alternator may very well be wasted even though it was "bench tested".
Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@aol.com (Bigjfig) wrote in message

My anologe vom is fairly close +-.25V by eye reading. The alt output at big red terminl reads exaclty the same as the the dash
Gil
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
--WebTV-Mail-16955-10244 Content-Type: Text/Plain; Charset=US-ASCII Content-Transfer-Encoding: 7Bit
Just buy a new alternator and battery... :-)
--WebTV-Mail-16955-10244 Content-Description: signature Content-Disposition: Inline Content-Type: Text/HTML; Charset=US-ASCII Content-Transfer-Encoding: 7Bit
<html> <body background="
http://community-2.webtv.net/zpods/bg/scrapbookFiles/importD90.jpg " bgcolor="#cccccc" text="#330000"> <br> <img src="
http://community-2.webtv.net/Z24PODS/z24pods/scrapbookFiles/importD15.jpg " width border=0 alt=me align=right> <br> <br> <br> <br> <br> <font size=3 color="#330033"><b><i> <marquee width="100%" scrollamount=6> ~ ~ ~ ~ ~ ~ I had to send poor "betsy" to the automotive junkyard in the sky 'cause she was falling apart w/ 225,000+ miles [R.I.P.]. Her replacement should fill her tires quite nicely though :-) ..... Road trip this spring.... Yeah.!!!!!!! </marquee></i></b></font> <br> <br> <br> <a href="http://coolstuffclickhere.com/mid/youvegotmail.wav "><img src="
http://community-2.webtv.net/zpods/tx/scrapbookFiles/importD1.gif " width border=0 alt=message align=right></a> <font size=2 color="#333333"><b><i>2000 Chevy Camaro Convertible<a href="http://community.webtv.net/Z24PODS/2000ccc "><img src="
http://community-2.webtv.net/Z24PODS/2000ccc/scrapbookFiles/importD18.jpg " border=0 width)5 alt="my chevy"></a> <br> "click pic for a close-up"</i></b></font> <br> <br> <br> <br> <br> <br> <center> <font size=2 color="#330033"><i><b>THE Z24PODS WEBSITE</b></i></font> <br> <a href="http://community-2.webtv.net/Z24PODS/Website /"><img src="
http://community-2.webtv.net/Z24PODS/z24pods/scrapbookFiles/importD33.jpg " widthE0 border=2 alt=website></a> </center> <br> <br> <br> <br> <center> <table height="109" width="141" background="
http://community-2.webtv.net/zpods/ca/scrapbookFiles/importD62.jpg "> <tr><td align="center"><br><br><br><br><b><font color="#999999"><a href="http://community-2.webtv.net/Z24PODS/irc2 /"><marquee width="57%" scrollamount="4">ENTER THE Z24PODS CHATROOM.!!! CLICK HERE NOW...... </marquee></a></font></b></td></tr></table> </center> <br> <br> <br> <br> <!-- BEGIN LOCAL BANNER --> <center><table cellspacing=3 cellpadding=1 border=4 bgcolor="666666"><tbody><tr><td alignnter bgcolor="#333333"><a href="http://www.ksdk.com /"> <font size=2 color="#999999" face="Geneva, Helvtica, Arial" effect=shadow> <i><b>St.Louis,<br>Missouri</b></i></font></a></td><td alignnter bgcolor="#333333"><a href="http://www.wunderground.com/US/MO/Saint_Louis.html "><img src="
http://banners.wunderground.com/banner/smalltemptr/US/MO/Saint_Louis.gif " heightU width border=0 alt="weather forecast"></a></td> <td alignnter bgcolor="#333333"><table border=1 cellpadding=2 cellspacing=2><td alignnter bgcolor="#000000"><img Reload="1" src="http://escati.linkopp.net/cgi-bin/clock.cgi?trgb 0000&srgbff00&prgb"ff00&timezone=GMT-0600" border=0 height"></td></table></td><td alignnter bgcolor="#333333"><table border=1 cellpadding=2 cellspacing=2><td alignnter bgcolor="#000000"> <img src="http://escati.linkopp.net/cgi-bin/date.cgi?trgb 0000&srgbff00&prgb"ff00&timezone=GMT-0600" border=0></td></table></td></tr></tbody></table> </center> <!-- END LOCAL BANNER --> <br> <br> <bgsound src="http://www.moonfairye.com/midicollection/music/bluemonday.mid " autostart=true loop> </center> </body> </html>
--WebTV-Mail-16955-10244--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@webtv.net (Z24PODS says... "Click Here") wrote in message

Oh ok - never thought of that--- (senoir moment)
Ah!!!! Alternator & Battery are NEW as origanl post
Latest trail: jumped small termial on Alternator to try to get it to energize: get up to charging cap of 13.5v - no luck
Can the ECM turn the charging on this guy?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

A new battery and alternator won't solve a wiring problem :). Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@aol.com (Bigjfig) wrote in message

It won't?? Them basterds lied to me!!!!!!!! Just like the time I bought a brake power boster. The parts guy really thought if you put this thing on, you'll get more power out of your engine! LOL....... Now come on! Somebody has to have had a simular electrical problem out there? or just intreprt how the charging system actually works - get it? ok? ie: can read the GM manual's curcutry schematic, which we have. get it? ok?
Before this post goes south, Thanks Gil

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

If ya can read the diagram and have the GM shop manual, I believe they have a troubleshooting chart in the manual. What did that have to say? :)
Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@aol.com (Bigjfig) wrote in message

Q: Does the ECM control any charging functions??? I'm gonna try a bone yard one next, if someone can tell me Y/N the ECM does have a charging system control/function.
Gil

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@cin.net (Gil) wrote in message

HEY OUT THERE!!!!!!!!!!!
A LITTLE HELP HERE PLEASE.
I'M STUMPED!
thx gil

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Gil:
You mentioned you have the GM shop manual for this vehicle. What does the troubleshooting chart in the book say? That's the first place to go and follow along.
It will lead you to the problem. Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@aol.com (Bigjfig) wrote in message

Ok I give. PLEASE Can anyone tell me if the ECM (brain box computer) has any bearing on the charging output???? Thanks Gil
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
no it don't even gm isn't that stupid. the big term should have battery voltage at all times.the field term should go hot when the key is on. charlie 69' firebird 400 H.O.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@cin.net (Gil) wrote in message

I'm a Ford man, so this GM stuff has got me stumped. I'd really like to get this thing on the road & not take it to a shop so I can pay them to guess like me. Any other idea's on what to try next? Please e-mail me also, Its hard to check all the groups. Thanks
Gil
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I hate stuff like this because its all really a guess unless you have the right trouble shooting manuals from the factory. Here are a few things off the top of my head.... First off, although it sounds weird it could be possible for an alt to check out fine on the bench but when it actually is in the car it wont charge. Who bench checked it and how did they do the bench check? Did they open it up and check everything inside with an ohm meter? I don't know which cars had this problem (I cant remember but I think it was a GM) but here it is anyway. As far as i can remember certain GM engines had a bad or insufficient ground going from the alternator itself to the engine. Even though the alt is mounted to a metal bracket that is mounted to the engine it still couldnt get a good enough ground and the alt wouldnt charge. It seems impossible but i've seen it happen. More than likely this isn't your problem but at least its something to think about. You could always run a wire from the alt mounting bolt to a really clean engine ground to see if it helps. These cars do have internal regulators right?
Mike MuscularMustangs.com http://www.muscularmustangs.com

down
alternator
going....
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The plug that plugs into the alternator:
One terminal is for the light/gauge, and one terminal excites the field. When the battery is fully charged, turn on the key with the white plug removed from the alternator to see if you are receiving current to the terminals on the white plug.
When it was bench tested, they put twelve volts to the field terminal in the alternator. If you aren't receiving voltage to the white plug when you turn on the key, the field isn't getting the current to cause the magnetism, hence. No charge.
First look at the fuses, possibly there will be a charge, alt, batt, gauge fuse. it might be as simple as that. If not, you're in for some diagnostics.
I think the web site is www.aldata.com and for like $25.00 you'll have access to every piece of diagnostic, and maintenance data for your car. Better than having a bunch of shop manuals, and what they don't have. Call the 800 number and they'll get it for you.
Refinish King

down
alternator
going....
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 28 May 2004 13:02:27 -0400, "Refinish King"

Close King, it's www.alldata.com
** To email a reply, please remove everything up to and including the underscore in my email reply header.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thank you kindly for the correction:
I like to help, not give out misinformation!
Sincerely,
Refinish King
wrote:

Call
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Alldata is good, but they rip off the information from the factory shop manual.
I've paid as little as $15 for the factory shop manuals for my cars. A Haynes will cost you that and be totally wrong! Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
If we were in the days of outhouses:
Sears catalogs were worth something for the purpose that you would use it for in an out house. I shudder to say, Haynes wouldn't even be good for that!
Refinish King
wrote:

car.
manual.
Haynes
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.