Painless wiring alt. hookup

[ssjones]

I currently have my system wired like the diagram on the left diagram of this .pdf file from painless. I am not getting a charge back to my battery. Any ideas? I have a 72 3/4 ton chevy. I have been fighting this too long and really need some help..... thanks.

http://www.painlesswiring.com/Manual...nstruction.pdf

[JimKshortstep4x4]

Do you have a one wire alternator?

Jim

[ssjones]

Here is what i have. i think it is called a one wire. there is a lug bolt on the back and NO external regulator.

[case_bt]

thats not a one wire it is an internal regulator but no one wire because of the other plug in the top of the alternator

[case_bt]

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

check out tthe following link and the complete web site this guy knows what he is talking about because I've talked to him twice for about 30 minutes each on company time

I've done most of his mods even the Ford type starter relay.

[VetteVet]

First of all, do you have an internal or external voltage regulator? An easy way to tell is the small harness plug, does it plug into the back of the alternator (external ), or on the top (internal). Are you doing a conversion from external to internal regulators.
Your PDF from painless only shows the output wiring from the alternator and does not show the wires to the alternator fields. That is the two terminals on the top of the alternator. Or on the back if it is stock. I assume you know what you have, but the painless harness might be different. If you have a one-wire alternator like Jim asked about then it makes a big difference in the wiring. Post back with what you have and what you have done and we can help you better.

[ssjones]

harness plugs into the top of the alternator. I dont know where to connect the red wire coming from the harness. The diagram in the painless manual shows the red wire from the harness being connected back to the lug/bolt. That can't be right because you cant shut the truck off when it is connected like that.
I have a white wire from the harness going to the white painless wire labeled alt. excitor.
The rest of my wiring is like what you see in the pdf file.
Thanks for your help.

[nandress]

Originally Posted by ssjones

harness plugs into the top of the alternator. I dont know where to connect the red wire coming from the harness. The diagram in the painless manual shows the red wire from the harness being connected back to the lug/bolt. That can't be right because you cant shut the truck off when it is connected like that.
I have a white wire from the harness going to the white painless wire labeled alt. excitor.
The rest of my wiring is like what you see in the pdf file.
Thanks for your help.

Which red wire? I just wired mine in last week (haven't run it yet, so it may not work either) and the only other red wire I remember besides 915 and 916 was for electric choke. And 915 and 916 are basically coupled at the fuse block, so it wouldn't really matter which goes to the alternator and which goes to the maxi fuse. You did use the high output alternator kit included with the wiring harness, right?

Is your maxi fuse good still? You may have accidentally blown it with an inadvertant short somewhere.

Also, wouldn't the 920 Pink wire going to your ignition determine whether the engine will run or not?

[ssjones]

Originally Posted by nandress

Which red wire? I just wired mine in last week (haven't run it yet, so it may not work either) and the only other red wire I remember besides 915 and 916 was for electric choke. And 915 and 916 are basically coupled at the fuse block, so it wouldn't really matter which goes to the alternator and which goes to the maxi fuse. You did use the high output alternator kit included with the wiring harness, right?

Is your maxi fuse good still? You may have accidentally blown it with an inadvertant short somewhere.

Also, wouldn't the 920 Pink wire going to your ignition determine whether the engine will run or not?

The red wire i am talking about is the one with the connector that connects at the 3:00 position on mine. Where did you install yours?

My maxi fuse is fine and there is also a 960 wire that goes from the maxi fuse the alt lug.

I did use the high output alt kit

[nandress]

Ok, here's the way I understood the high amp kit.

There were two wires in the high amp kit, the 10 guage 960 wire and the 8 guage wire that goes from maxi fuse to starter. The 10 guage 960 had a terminal already crimped on it with the boot. That terminal was to go to the terminal on the alternator and the other end directly to the maxi fuse.

On mine, I cut that terminal off and crimped a new terminal with 960 and 915 together so that I would have only one terminal connecting to my alternator (as the stud was not very long and I don't think I could have had two ring terminals on it at the same time).

Needless to say, as long as you have a wire going from the output of the alternator to the maxi fuse and another wire going from the maxi fuse to the starter and your battery cable going to the starter, you should have charging happening. What would happen if you bypass the maxi fuse (temporarily, of course)? Also, do you have to jump start every time?

I think where all the other posters were going is that if your alternator is not being excited then it is not going to be outputting voltage. What kind of voltage are you getting out of your alternator when it is running? Just take a voltmeter to the output terminal and touch the other end to a ground.

[ssjones]

Originally Posted by nandress

Ok, here's the way I understood the high amp kit.

There were two wires in the high amp kit, the 10 guage 960 wire and the 8 guage wire that goes from maxi fuse to starter. The 10 guage 960 had a terminal already crimped on it with the boot. That terminal was to go to the terminal on the alternator and the other end directly to the maxi fuse.

On mine, I cut that terminal off and crimped a new terminal with 960 and 915 together so that I would have only one terminal connecting to my alternator (as the stud was not very long and I don't think I could have had two ring terminals on it at the same time).

Needless to say, as long as you have a wire going from the output of the alternator to the maxi fuse and another wire going from the maxi fuse to the starter and your battery cable going to the starter, you should have charging happening. What would happen if you bypass the maxi fuse (temporarily, of course)? Also, do you have to jump start every time?

I think where all the other posters were going is that if your alternator is not being excited then it is not going to be outputting voltage. What kind of voltage are you getting out of your alternator when it is running? Just take a voltmeter to the output terminal and touch the other end to a ground.

Makes more sense. I was missing the stater wire to the maxi fuse. Did not see that in any documentation.
I still dont know where to hook up the red wire on the flat connector that plugs into the top of the alt.

[ssjones]

Ok. I am getting 12.78 volts. Do I have a bad alt. ? What could the chances be that i have a bad alt and just finished with the wiring. ????

[HD2000]

The red wire on the flat connector is supposed to be jumpered to the red wire on the lug on the back of the alternator?
I've also installed the Painless kit but progress has stalled recently (about 85% done) so I can't gaurantee this.

[ssjones]

Originally Posted by HD2000

The red wire on the flat connector is supposed to be jumpered to the red wire on the lug on the back of the alternator?
I've also installed the Painless kit but progress has stalled recently (about 85% done) so I can't gaurantee this.

I tried that and that is when the engine would not turn off until I pulled that plug. All in all it is a great kit and this has been the only thing kicking my butt. I

[HD2000]

Does it appear to charge with that red wire jumpered?
Some people have reported similar problem (truck won't shut off) and there is a thread somewhere in the forums. The fix if it does not shut off is to add a diode to the exiter wire. I sent Painless a question (a couple actually) and here is the response to the one regarding the truck not shutting off:
"You may not, but most likely will have to put the 276-1661 (Radio Shack) diode in the 914 exciter wire somewhere by the alternator. The diode will have a painted end or a stripe painted on one end, this strip will point to the alternator "
If you do figure out the problem please let us all know what the solution was (as it may turn out that we all have the same issue)

[ssjones]

Originally Posted by HD2000

Does it appear to charge with that red wire jumpered?
Some people have reported similar problem (truck won't shut off) and there is a thread somewhere in the forums. The fix if it does not shut off is to add a diode to the exiter wire. I sent Painless a question (a couple actually) and here is the response to the one regarding the truck not shutting off:
"You may not, but most likely will have to put the 276-1661 (Radio Shack) diode in the 914 exciter wire somewhere by the alternator. The diode will have a painted end or a stripe painted on one end, this strip will point to the alternator "
If you do figure out the problem please let us all know what the solution was (as it may turn out that we all have the same issue)

I will check that.
I do think I may have a problem with the alt because I am only showing 12.78 volts off the lug on the alt. when the truck is running.

[nandress]

12.78 volts does seam pretty low. Most of the batteries and alternators I have seen are in the 13.8 to 14.2 volts region when charging properly. At 12.78 you would be barely equilized with a half charged battery. When you took that voltage, were you testing at idle? Try it again but run up to 2000-2500 rpm and see if there is a difference. Also, take a voltage across your battery before, during, and after to compare. If your battery and alternator are wired up right, the voltage should be the same while the alternator is spinning.

I am still not clear about your other red wire, but then again I have a one wire alternator so I do not have to worry about all the extra stuff!!

[ssjones]

Thanks for all the help. I installed the suggested diode from member HD2000 and now my engine turns off with the key and the Alt. is charging. I wish Painless would have included a little side note in their docs. All in all it has been a nice install.