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Discussion Starter #1
Here is my latest dilema, Im still trying to get my 69 to charge.

With the Key on, engine not running, all of my breakers have power (on both sides) except the Heater, Wiper, Radio, Accessorie, and Ins Lpms. All the others have power ??????

Here's another catch, I jumped the blue wire on the back of my alternator with the red wire in the back of the alternator (to test my alternator), and guess what, the Wiper, Radio and accessorie breakers all of a sudden get juice even when the key is off. The heater breaker stayed dead. BTW, The alternator charges when I did this.

Im guessing someting is shorting behind the breaker box. I have never removed one of these before. If I take off the two corner screws, will this whole fuse panel just come off so I can look behind it and see if everything is OK? It is my understanding that the one black wire coming from the horn relay bus bar is the one that powers all the breakers

Thanks
 

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The 16-ga. black wire from the horn relay screw terminal is actually a fusible link, which is spliced to a 12-ga. red wire which provides all power to the fuse block. Remove the engine-side connector (bolt in the middle), then remove the two corner screws from the inside and pull the fuse block away from the dash. Then you can bend the plastic legs that hold the front and back of it together and see if there's any corrosion or broken buss bars in it that are causing dead fuses.
:beers:
 

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efd75 said:
Here is my latest dilema, I'm still trying to get my 69 to charge.

With the Key on, engine not running, all of my breakers have power (on both sides) except the Heater, Wiper, Radio, Accessories, and Ins Lpms. All the others have power ??????
First, they are called fuses,
Heater, Wiper, Radio, Accessories, all get their power from the IGN switch. Ins Lpms gets its power from the tail lamps circuit, which gets its power from the headlight switch. Do the headlights work? Might be a problem at the 12g 4 way splice or you have 2 separate problems. :sad: IGN switch or the connections to it might be bad, see pic
http://www.madelectrical.com/images/chevym1.jpg
efd75 said:
Here's another catch, I jumped the blue wire on the back of my alternator with the red wire in the back of the alternator (to test my alternator), and guess what, the Wiper, Radio and accessories breakers all of a sudden get juice even when the key is off. The heater breaker stayed dead. BTW, The alternator charges when I did this.
This is called backfeeding. The blue wire comes from the gen lamp, and there is a extra wire from the IGN switch to power the blue wire incase the GEN lamp burns out. The fuses in question were getting power because you supplied it through the blue wire. Sounds like a broken connection between the IGN switch and the fuse box or the IGN switch itself. Dot not leave the jumper in place, with the car running, putting 12 volts on the "F" terminal forces the alternator to max output. You can kill the alternator and a lot of other things if left in place to long. If you are having charging problems, its most likely related to the fuse power problem, as the power comes from the IGN switch.
efd75 said:
I'm guessing something is shorting behind the breaker box. I have never removed one of these before. If I take off the two corner screws, will this whole fuse panel just come off so I can look behind it and see if everything is OK? It is my understanding that the one black wire coming from the horn relay bus bar is the one that powers all the breakers

Thanks
Yes, it powers all fuses eventually, but some get their power from the headlight switch or the IGN switch.
 

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Discussion Starter #4
Thanks for the reply Undee,

Yes the headlights work fine, including the high beams. Where is this 12g 4 wire splice you mention?

Here is another funny thing, when I removed the "jumper wire" on the back of the alternator, (with car still running), all the fuses kept their power?????? Then when I turned the car off and on again, there was no power to them. Go figure.

Would you happen to know what color wire it is I should be looking for that comes from the ignition switch that seems to be the trouble maker? If this ignition switch is bad, wouldn't the car not start?

I really cant work on this until Saturday, so getting as much info prior is helping alot.

Thanks
 

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efd75 said:
Thanks for the reply Undee,

Yes the headlights work fine, including the high beams. Where is this 12g 4 wire splice you mention?
Its right near the fuse box, see pic in link
efd75 said:
Here is another funny thing, when I removed the "jumper wire" on the back of the alternator, (with car still running), all the fuses kept their power?????? Then when I turned the car off and on again, there was no power to them. Go figure.
I would bet the IGN switch is bad or a connection to it.
efd75 said:
Would you happen to know what color wire it is I should be looking for that comes from the ignition switch that seems to be the trouble maker? If this ignition switch is bad, wouldn't the car not start?

I really cant work on this until Saturday, so getting as much info prior is helping alot.

Thanks
I don't have a wiring schematic for a 69 but most yrs are pretty close. 2 12g reds supply power to the IGN switch, one for the 12g purple for the starter, the other for the coil and the fuse box. Power out is, 12g purple for starter, 12g pink for coil and fuse box, 12g brown for ACC position to fuse box, 12g orange from fuse box that powers 20DG, 20DG to temp light, 20g brown / with white stripe to power charging system incase idiot light burns out. Check all of these connections.

Since you are having charging problems, this was posted by another member on Team Chevelle on how it works and to troubleshoot a externally regulated charging system and is well written.


Originally Posted by Peter F.
I dug this out from before, hopefully it help. If not, just post or send me your questions.

I'll try to provide a simplified explanation of how the externally regulated alternator and regulator work here. This explanation starts from a parked car with engine off state.

The regulator brown #4 wire is connected through the light bulb to 12V whenever the key is in the ON position. The other end goes through a set of points in the regulator and then out the F terminal to the field winding in the alternator. So some current begins flowing in the field winding from this connection. The little bit of current flowing produces a weak magnet field in the alternator and also lights the bulb.

When you then start the car, the weak magnetic field from above begins rotating which makes the alternator producing a little bit of voltage. This voltage is fed from the alternator to the regulator on the white regulator #2 wire. This wire connects to a coil in the regulator and turns on a contact when the voltage goes above 3.2V.

Once the contact turns on in the regulator the #3 and #4 terminals are connected together. Terminal #3 is battery power so this puts battery power on both sides of the bulb and turns it off. This means the brown #4 wire should go to +12V. Also, this connects the field terminal right to battery power but still going through the points.

When the battery voltage goes above a set level, the F terminal is disconnected from the battery power by the points I kept mentioning. Then the voltage drops and the points close again. This on-off cycling happens rapidly and is how the voltage gets regulated.

From the above (KOEO = key on engine off and KOER = key on engine running).
F or #1 terminal (field) - KOEO = #4 slight voltage, KOER = 9-12V typically
#2 terminal (sense) - KOEO = 0V, KOER = >3.2V
#3 terminal (Battery) - KOEO = 12V, KOER = 12V
#4 terminal (light) - KOEO = F slight voltage, KOER = 12V

By 12V above I mean battery voltage, which may be 12V when engine is off but could be up to 14.5V when engine is running.

Check the light: Ground the brown #4 terminal wire at the regulator. When grounded the light should come on. If you don't have a light then skip this test. Test this with the connector off the regulator.

Checking the alternator: Jumper the blue wire F terminal to the battery post on the back. This should make it easily crank out 16+ volts. Next, connect a troublelight between the battery post and the F terminal. The light should come on and you should measure > 3.2V at the other alternator terminal. If it passes these tests, then it's in the regulator or wiring.

Checking the wiring: At the regulator connector jumper the brown light wire (#4) to the F terminal (#1) and you should be able to measure >3.2 volts on the other alternator terminal or terminal #2 of the regulator connector. If these tests pass, it is in your regulator.

When doing these tests, make sure you turn off or pull the fuses for any added electronics that you can. The alternator test can produce enough voltage to damage stuff.

Peter
 

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Discussion Starter #6
One problem solved, another arised.

Hats off tho Undee, I found two unconnected wires at the ignition switch, the double brown (my alternator) and the orange. THe car is charging now.

Now the new problem, it seems that after running for about 10min, the car slowly dies after it gets to 170 degrees. If I let it sit, and start it, it will run but slowly die out. I noticed that when I turned the headlights on, it died immediatley. I do have suspicion that the coil and the electronic points are not good, and I might have burned it out with all the "key on" testing I did, and the high voltage when I backdoor jumped the alternator. Does this sound like a symptom of a bad coil/points?

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efd75 said:
One problem solved, another arised.

Hats off tho Undee, I found two unconnected wires at the ignition switch, the double brown (my alternator) and the orange. THe car is charging now.
:thumbsup: :thumbsup: :thumbsup:
efd75 said:
Now the new problem, it seems that after running for about 10min, the car slowly dies after it gets to 170 degrees. If I let it sit, and start it, it will run but slowly die out. I noticed that when I turned the headlights on, it died immediatley. I do have suspicion that the coil and the electronic points are not good, and I might have burned it out with all the "key on" testing I did, and the high voltage when I backdoor jumped the alternator. Does this sound like a symptom of a bad coil/points?

Thanks
Replace the points and go from there.
 
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