Battery not charging

[Big "O"]

Thursday, we finally got blue skies here in San Antonio and I had the opportunity to drive the car to work. Leaving work, the GEN light turned on and the VOLTAGE meter showed the battery not charging. I have checked the alternator at 2 different auto parts and it checked out good. Checked to make sure I had power at the alternator. Checked the starter for good contacts. The battery indicator does not show a charging mode, it's just reading the volts of the battery.
If anyone has had similar problems or know of a fix, please help me out. :confused

 

[DDLS3]

What was the voltage when the alternator was tested? In order to proper charge the battery the alternator must produce at least 13.5 volts to a maximum of 14.1 volts. If it is less than the 13.5 volts then the alternator has a failing/failed voltage regulator and needs to be repaired.

 

[JonM]

Have the battery itself checked...Have it checked while fully charged.

 

[vigman]

There has to be +12

At one of the two small terminals.. I'll have to dig out the book of WISDOM! Its the red on the 2 pin connector.. if thats not hot.. no chargy! The brown line is the charge light.


Vig~

 

[Big "O"]

Thanks for the info so far. The alternator was checked and was putting out 14 volts. I did check for output from alt and checked out okay. I'm quite sure the bat is good since I charged it and held a charge.
Could this possibly be a fault with the Voltage meter?

 

[vigman]

Well.. yes & no

In the 79-82 series there was a connector by the firewall ( AC heater box side ) that would get CHARBROILED.. and power distribution might not have happened correctly..

So your Batt might be OK.. and ALT itself might be ok..but the plumbing inbetween is a bit iffy.


I'll go find a post.

http://corvetteactioncenter.com/for...9&perpage=15&highlight=Connector&pagenumber=1


Vig~

 

[81NMVETTE]

Big O
I had a charging problem also. I found the wire from the Alt to the batt. had opened. I always had less than 12V showing on the meter (on the dash)
Vig man is right you need 12V on one of the small wires allso on the other small wire you need to see aprox. 6 V they drop 12V to 6V by running the voltage thru the charging light bulb. If there is not 6 V there then eather the bulb is burned out or the fuse is bad.(its the same fuse for your horn).
It sounds like all of your Voltages are there.And you did say that you saw 13V on the output of the Alt. What is the voltage at the Battery (eng running) ? if it is less than what you read on the output of the Gen then you might have an open wire. Allso check that lil connector block by the battery make sure it is a good conn. If you have at least 13V at the battery then the problem would be with the montoring part of the system.
GL
Earl

 

[Big "O"]

The battery is not charging at all and is being drained each time I start the engine. I'll check the wires coming from the alternator for continuity. My understanding is the red wire attached to the 2 wire male fitting on the alternator is the one to check for charging the battery. Is this correct or should I be looking at the one wire on the alternator that has the nut on it?

 

[vigman]

Pop Quiz.. Charging system repair

The battery is not charging at all and is being drained each time I start the engine.

Test #1 engine off Batt hooked up

Remove the Red wire of the back of the ALT

hook a a test light to the red wire you now removed ( DANGER.. THIS WIRE IS HOT... Do NOT let it touch GROUND.. or you will have MORE wiring problems) Is this wire HOT?

If yes.. put it back on the back of the ALT.

If no... you have a fusible link blown.

Test #2

Remove the 2 pin connector from the side of the ALT( big red/ small brown).... turn the key ON.. See if 12 volts is there on the red wire.


If yes.. replace the plug

If no.. we gotta dig.

report back!


Vig~



I'll check the wires coming from the alternator for continuity. My understanding is the red wire attached to the 2 wire male fitting on the alternator is the one to check for charging the battery. Is this correct or should I be looking at the one wire on the alternator that has the nut on it?

 

[81NMVETTE]

My Guess is with Vigman's first test.
I would try his #1 test and see if you have V on the large red wire. It is the big red wire that is held on the back of the Alt. with a nut. you ought to see 12V on this wire at all times as it comes straight from the Battery (at least on my 81)
If you see no V on this wire then You might have a blown fuse link. However I did not see one on my car but it might have been replaced with a solid wire. (I hate these links BTW)
Those small wires that are on that small connector are to set the field for charging. the red one is hot all the time and the brown one is hot when the key is turned on. I dont think the small wires are the issue as you have good output on the Alt.

How are you testing for Voltage ? Are you using a multi meter ?
Earl

Big O if you want to give me a call just E-Mail me and I will give you my cell #

 

[Big "O"]

Still can't find the problem. I will try again Friday. I'll take the battrey off the car and place the one from my truck to see if maybe something is wrong there. If this doesn't do the trick, off to Sears I go.

 

[page62]

Don't be so sure about that battery! By the way, Sears can check your entire charging system. And perhaps they do it for free -- give 'em a call.

By the way, are you coming to our car show in Boerne on April 12th? Check out www.texas-corvette-association.org

 

[geekinavette]

One thing to watch out for is when these shops "test" the alternator they usually will run it with NO LOAD. This is a completely different scenario than when the alternator is on the car, providing current to the car's electrical system. You might check with the shops where you had it tested and ask them if they place an electrical load on the alternator when they tested it (I sincerely doubt it).

More than once I've seen the parts store say a alternator (or starter) was good when in fact it was bad.

Good luck,

Bill

 

[Pappy]

I would have the battery charged and load tested first, Then go with Vigman's suggestion, Sometimes you can have something drawing the power from the battery even with it off,but that gets involved in locating the source. Any recent additions like a radio or alarm system or anything else that may draw power while off?

 

[Big "O"]

Okay, this what I have managed to find so far. I went ahead and checked for output on the output lead and it is hot, with engine turned on 33v-36v, Yipes! The 2 wire connector, the red always has 12v, the brown wire has 12 with key on except when car started then reads around 19v with car started. Still can't figure where the problem is! I managed to read material from another site that some cars are fitted with a charge relay. Does the 79 have this relay? If so, where is it? Somewhere the charge from the alternator is not reaching the battery. Does anyone have a wiring diagram they can post?

 

[Big "O"]

Hey guys, I traced down the problem. Turns out it was a bad connection in the wiring coming inside from the firewall. I have a co-worker who lent me his Haynes book showing the wiring diagram in full detail. The Haynes book I have doesn't give you the full detail. The numbers on the books match but my freinds is the older book. His book was printed in England 1979, 1982, 1986 while mine was in USA 1991, 1999. I also noticed my 79 was matched to the 1980 wiring diagram, so I used it for my tracking. Thanks for the help and if I may suggest, get your hands on the England printed repair manual.

 

[FLATOUT427]

It's Been A Few Years But I Had Problems With My '68 Not Charging. I Finally Tracked It Down To A Broken Resistence Wire That Connected To The Voltage Regulator.