The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-03-2004, 08:15 PM   #1
69 Short Fleet
Registered User
 
Join Date: Nov 2002
Location: Kelowna B.C. Canada
Posts: 1,086
Thumbs down My Charging Sys. Is Still NOT WORKING!!!

Changed alt. (another new one) and it has the same voltage as my battery 12.2 volts I have gone through absolutley everything I can think of........ One other thing I should mention is my idiot lights in the (brake & Battery) will not light up (bulbs are OK I'm going out to check voltage right now), my gas gauge is intermittant and my backup lights dont work.
69 Short Fleet is offline   Reply With Quote
Old 08-03-2004, 10:41 PM   #2
9footfan
get up! stand up!
 
9footfan's Avatar
 
Join Date: Apr 2004
Location: austin,tx
Posts: 345
jusy my 2cents--make sure to check ALL GRDS. also i had a real nightmare locating an electrical problem w/my 67 c-10 and i finally (after months of frustration as the problem was intermitten) traced it to the grd block inside the engine compartment on the inner passenger side fender directly next to the battery. the connections there i was tightening but the nut would always back off and become just loose enough to cause some strange things to happen. i replaced the nut, reterminated the connections and have had zero problems since. also you should try replacing the pickup wire from the battery to this connection block as this is simple & cheap and if that wire is wrong guage or has a "high" open in it it will cause wierd stuff as well. just my 2cents. hope maybe that can help. ps check ALL GRDS.
__________________
9FT STEPSIDE CLUB
40 1-1/2 ton stake
67 c30 disassembled & for sale
70 gmc 3500 canadian 9 foot "fenderside" pickup
06 silverado
71 vet enjoyed by my retired father

wtb-67 chevy 1 ton 9ft stepside-in perfect condition
9footfan is offline   Reply With Quote
Old 08-03-2004, 11:38 PM   #3
71swb4x4
Senior Member
 
71swb4x4's Avatar
 
Join Date: Nov 2003
Location: Brookings, SD
Posts: 10,497
Start all over with the wiring. Don't remove it all and replace it but check every wire. Run an ohmmeter on them to be sure that you don't have a broken wire. Make sure they are all hooked up correctly. Basically start with the basics again and go slow.
When it something causing you this many problems it's probably something cheap to fix but hard to find.
__________________
Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.
71swb4x4 is offline   Reply With Quote
Old 08-04-2004, 12:01 AM   #4
67cst
i love summertime
 
67cst's Avatar
 
Join Date: Jul 2002
Location: Kelowna BC
Posts: 4,303
doug, stick with it ! i had some wiring nightmares with my truck too, but we finally did get it, also--sorry i didnt stop by this past weekend, it was pretty hectic right from friday when i got off to last night when i hit the hay...ill come by one of these days to say hi,

Derek
__________________
1967 shortbox stepside Chevy, 365 hp 327, th400.

GLOVE BOX LIGHTS FORSALE, click link for info

http://67-72chevytrucks.com/vboard/s...d.php?t=273724
67cst is offline   Reply With Quote
Old 08-04-2004, 01:12 AM   #5
9footfan
get up! stand up!
 
9footfan's Avatar
 
Join Date: Apr 2004
Location: austin,tx
Posts: 345
71swb is right on..your problem is most likely very simple and very hard to find. stick with it and remind yourself that you love your truck. take it one step at a time and quit or take a long break if you get frustrated.
__________________
9FT STEPSIDE CLUB
40 1-1/2 ton stake
67 c30 disassembled & for sale
70 gmc 3500 canadian 9 foot "fenderside" pickup
06 silverado
71 vet enjoyed by my retired father

wtb-67 chevy 1 ton 9ft stepside-in perfect condition
9footfan is offline   Reply With Quote
Old 08-04-2004, 01:27 AM   #6
DMNCLNR
Registered User
 
DMNCLNR's Avatar
 
Join Date: Jun 2004
Location: Orange County Cali
Posts: 258
In my days of electrical trouble, polarizing is the most commonly overlooked task! also the voltage regulator going bad will do the same thing, only your battery will get really hot. mine almost melted!
__________________
64 caravelle camper
58 Vert bug
64 SS nova for sale 14k http://www.stevesnovasite.com/forums...ad.php?t=46362
Wanted: any early V.Ws any condition!
DMNCLNR is offline   Reply With Quote
Old 08-04-2004, 01:27 AM   #7
69 Short Fleet
Registered User
 
Join Date: Nov 2002
Location: Kelowna B.C. Canada
Posts: 1,086
Thanks for all the encouragement guys! I ABSOLUTLEY REFUSE to loose this battle or pay someone to fix it for me (LOL) I'm startin fresh again tommorow, Regards Doug
69 Short Fleet is offline   Reply With Quote
Old 08-04-2004, 01:37 AM   #8
chickenwing
Lovin' Life in Miss.!
 
chickenwing's Avatar
 
Join Date: Mar 2004
Location: Puckett, Mississippi
Posts: 1,937
I would pull all the fuses and run an ammeter across the terminals to determine wich circuit was pulling amps with the key off. If there is no draw at the fuse block at least this narrows it down to the voltage regulator, alternator or starter. You can even run the ammeter between the pos bat cable and battery terminal to deternine amount of current flowing, or between any suspect component. Make sure your ammeter can handle the expected amperage draw. Probably will. Slow leak.
Hope this helps.
Rich
__________________
The truck... you hear that? No really, you did hear that?!!!
chickenwing is offline   Reply With Quote
Old 08-04-2004, 05:29 AM   #9
dwaite72lnghrn
Registered User
 
Join Date: Jun 2002
Location: central pa
Posts: 1,525
It really sounds like your grounds are screwed up. With the red wire off the alternator engine running measure the voltage output of the alternator from the case to the terminal the red wire came off, then measure from the frame, Then measure from the rad support if there is any difference it is a grounding issue. Did you replace the voltage reg with a solid state unit of OEM relay unit? just my $.02
__________________
72 longhorn c30 502BB/th400/fact air/4.11rear/ custom camper
72 bug(the better half's) under reconstruction
2009 HHR aqua blue
71 GMC k20 350/sm465
2009 Chevy hd3500 6.6 Victory Red crew cab dually
Dave & Jeanne
dwaite72lnghrn is offline   Reply With Quote
Old 08-04-2004, 06:02 AM   #10
69 Short Fleet
Registered User
 
Join Date: Nov 2002
Location: Kelowna B.C. Canada
Posts: 1,086
-chickenwing, I already tried checking each and every fuse terminal location (with the fuse pulled) and found no voltage (key in off position), also I have a new external voltage regulator and I even tried it with the old one (I'm sure its good as I took the cover off and both coils look fine and the contacts look fine as well).

-Dave, I will try what you mentioned, I also installed a 10 ga. ground wire from the rad support to the frame and have checked continuity on all grounds and checked all wiring circuts for continuity.

You guys are probably right though, its simple.... just hard to find. Doug
69 Short Fleet is offline   Reply With Quote
Old 08-04-2004, 08:04 AM   #11
Southpa
Registered User
 
Southpa's Avatar
 
Join Date: May 2000
Location: Victoria, BC, Canada
Posts: 2,410
I seem to remember the horn relay was a common culprit that caused a lot of grounding problems with these trucks. Did you search the archives for previous posts on battery charging problems? You should be reading at least 13.8 V across the battery when running. I went thru the same problems years ago. A friend (mechanic) and I did all the troubleshooting and still couldn't find the loss of charging voltage. Replaced battery, voltage regulator and rebuilt alternator and was still only getting negative voltage (~11 volts) across the battery when running. The quick and dirty solution was to bypass all the systems that might have ground faults by running a heavy wire from the back of the alternator directly to the positive battery post. Everything worked fine after that.
__________________
1970 GMC 1500 Custom
Original 350/TH350
Victoria, BC, Canada


You can wish in one hand and crap in the other.
See which one gets filled first.

Last edited by Southpa; 08-04-2004 at 08:22 AM.
Southpa is offline   Reply With Quote
Old 08-04-2004, 12:51 PM   #12
thisolechevy
Registered User
 
Join Date: Jun 2004
Location: Gainesville, Fl
Posts: 382
WOW!!!! yes I love doing this!! I just had this same problem (like this morning) my charging system was all messed up, three new alternators, 2 new batteries, a new starter, and still the same thing no charge. VOLTAGE REGULATOR get a new one and all problems solved.
__________________
Man I need another 67-72!!!
thisolechevy is offline   Reply With Quote
Old 08-05-2004, 08:25 PM   #13
chickenwing
Lovin' Life in Miss.!
 
chickenwing's Avatar
 
Join Date: Mar 2004
Location: Puckett, Mississippi
Posts: 1,937
Quote:
Originally Posted by 69 Short Fleet
-chickenwing, I already tried checking each and every fuse terminal location (with the fuse pulled) and found no voltage (key in off position),
Ummm... If you just checked for voltage with the fuse pulled you could only read voltage on the battery side of the fuse.
If you pull the fuse and hook an ammeter across both sides (help me with this guys,been awhile, in series?) you can see if there is current draw throught the fuse. If you find a fuse terminal with current running through it: you then isolate each component in that circuit pull, its power wire and hook up your ammeter between the power wire and the component and look for the current draw.
Doing it this way you can quickly isolate if it is a fused circuit or before the fuse block. Hope this helps.
Rich
__________________
The truck... you hear that? No really, you did hear that?!!!
chickenwing is offline   Reply With Quote
Old 08-05-2004, 09:38 PM   #14
bgood
Registered User
 
bgood's Avatar
 
Join Date: May 2004
Posts: 80
Unhappy 69SF check these links

They're a little hard to follow, too technical, but if you read closely you can understand the term of "remote voltage sensing".
I have some experience with Industrial and residental electronics and I have struggled with it also, just this past week in fact!
My problem stemmed from grounding out the low pressure switch on the back of my new Vintage Air unit to the firewall. I had wired the unit for switched supply voltage from the fuseblock and when it shorted it burned the brown wire leading to the back of the ignition switch in two. This caused my generator light to come on and rendered my charging system inoperable. I suspect the brown wire is the charging system sensing wire which was a single strand variety and I assume it is Nichrome or something similar to give it a higher resistance which is needed to help the circuit work. After making the repairs to the wire and insulating the pressure switch from ground I had to replace the voltage regulator. Not sure the local parts people can still troubleshoot\test these for us anymore.
Hang in there it will come to you just try to take it slow and methodical. Bill




http://www.madelectrical.com/electri...esensing.shtml

http://www.powermastermotorsports.co...ternators.html

This site has very anoying pop-ups so I list it last!

http://63novass.tripod.com/diagrams.htm
__________________
1967 C10 Short,Step
283\1460 Holley HEI Ign.
Borg Warner T56 6 Speed!
A-1 Electric life pwr windows
PS,PB,Tilt
275\60R'S on Alum Mags all around
Vintage Air A\C
Grey cloth Buckets
bgood is offline   Reply With Quote
Old 08-05-2004, 10:22 PM   #15
69 Short Fleet
Registered User
 
Join Date: Nov 2002
Location: Kelowna B.C. Canada
Posts: 1,086
OoooooKkkkkkk: I think I'm understanding now, I was measuring DC voltage between the fuse terminals at the fusebox when I should be measuring DC amperage (current) at the same location to determine which leg of my elec sys. is the trouble maker, is that correct? Also I checked the charging sys with my battery charged up (13.2 volts) and it still is not working so I'm going to look into it somemore right now, Thanks VERY much for all your helps guys, Doug
69 Short Fleet is offline   Reply With Quote
Old 08-05-2004, 10:38 PM   #16
jose
Registered User
 
jose's Avatar
 
Join Date: Feb 2001
Location: Salem , Oregon 97301
Posts: 1,796
Did you check your voltage regulator ?
__________________
68 GMC 4x4 SWB



jose6772@yahoo.com
jose is offline   Reply With Quote
Old 08-06-2004, 12:20 AM   #17
69 Short Fleet
Registered User
 
Join Date: Nov 2002
Location: Kelowna B.C. Canada
Posts: 1,086
jose, I bought a new one hooked it up and nothing (alt is putting out 0 I am getting slightly less DC voltage than my battery) My battery has 13.20 DCV engine off and I'm getting 12.80 DCV at the battery & Alt. with engine running, I then reinstalled the old one (pulled the cover off and the primary & secondary coils look fine as well as the contact arms and contacts) and tried the old one and it still won't work. The one odd thing is my brake light and battery light (idiot lights) in the dash do not work, the bulbs are ok but I'm going to check if for voltage to them tommorow. Also what grounds the instrument cluster? I want to check that out as well. This has now turned into a week long headache and by far the hardest thing I've ever had to fix in my life! Regards Doug
69 Short Fleet is offline   Reply With Quote
Old 08-06-2004, 02:22 AM   #18
69 Short Fleet
Registered User
 
Join Date: Nov 2002
Location: Kelowna B.C. Canada
Posts: 1,086
Hang on here a cottin pickin minute!!! It just hit me like a ton of bricks... I noticed my horn relay connector was diconnected and there is a large red wire (8 or 10 Ga.) that goes into it and a green wire (same gauge) going out of it. These wires look way too large to be horn related, could it be that the main elec. splice for the truck elec. runs through the horn relay?????? I just reconnected the thing but its too late to flash up the truck tonight, I'll be checking this out first thing tommorow, this could explain a lot of things, regards Doug
69 Short Fleet is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:38 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com