Wiring for dummies

[faribran]

i am also "wiring challenged"... fixit-p, keep it up.. i am trying to learn...... some good info, guys... thanks

[thebeast61]

ok i tried to clean them up but not sure if the colors will show so i labeled them. Hope this picture helps.
[IMG][/IMG]

[thebeast61]

this is a pic of the back and front of my ammeter
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[IMG][/IMG]

[thebeast61]

I appreciate the schematic but i dont understand those. It makes no sense to me when i look at them.

[fixit-p]

Originally Posted by thebeast61

I appreciate the schematic but i dont understand those. It makes no sense to me when i look at them.

No problem, the diagram was to illustrate how the ammeter is wired would have made a factory ammeter an external shunt type. But from your picture it would seem that the ammeter you have is aftermarket so therefore most likely an internal shunt (would also explain why you have both charge light and ammeter).

Along with the diagram I posted a picture showing what wires to connect.

At the reg.
Big brown and red together.
Small brown and blue together.

At the alt.
Big brown to batt terminal.
Blue to # 1 terminal
#2 terminal either jump to batt terminal (or big brown and red connection at the reg.)

The other wire was a ground not needed or you could connect 1 side to the fender well and the other to the ground lug at the alt, but again not needed for the alt to work but lighting could benefit from the additional grounding.

Re-read the thread all you need is already here just connect the text with the pictures and you'll be ok.
Where was the wire with the fuse holder originally connected to?

[Blue72slab]

You might consider replacing the ammeter with a voltmeter while o are doing this. A lot of current is going through that type and it is a common place to have a problem because of poor connections/heat. It will be easy to wire and more useful IMO. There are a couple of extra wires in the picture that may run power to other things you might have to trace down and connect somewhere else.

[thebeast61]

Originally Posted by fixit-p

No problem, the diagram was to illustrate how the ammeter is wired would have made a factory ammeter an external shunt type. But from your picture it would seem that the ammeter you have is aftermarket so therefore most likely an internal shunt (would also explain why you have both charge light and ammeter).

Along with the diagram I posted a picture showing what wires to connect.

At the reg.
Big brown and red together.
Small brown and blue together.

At the alt.
Big brown to batt terminal.
Blue to # 1 terminal
#2 terminal either jump to batt terminal (or big brown and red connection at the reg.)

The other wire was a ground not needed or you could connect 1 side to the fender well and the other to the ground lug at the alt, but again not needed for the alt to work but lighting could benefit from the additional grounding.

Re-read the thread all you need is already here just connect the text with the pictures and you'll be ok.
Where was the wire with the fuse holder originally connected to?

Thank you that helps so much. I know the wire with the fuse went to the regulator but its been so long since i took it off i cant remember which post it connected to.

[thebeast61]

Originally Posted by Blue72slab

You might consider replacing the ammeter with a voltmeter while o are doing this. A lot of current is going through that type and it is a common place to have a problem because of poor connections/heat. It will be easy to wire and more useful IMO. There are a couple of extra wires in the picture that may run power to other things you might have to trace down and connect somewhere else.

what would i do different to put in a voltmeter?

[thebeast61]

ok i got it wired up just like you said but it dosent appear to be charging according to the ammeter. It jumps over to negative when i crank it then it sits on negative 1 or 2 while its running. What should i do to check to see if its working? I know it may just be a bad gauge but it was working before so im thnking its the wiring.

[thebeast61]

Here are some pictures so you can verify my work. please ignore the ugly tape job. i will pretty this up later.

[fixit-p]

Looks like it should work. The best way to tell if it is charging is with a voltmeter, check the battery voltage with engine off to get a baseline reading then again with the engine running that will be your charge voltage. If the readings are the same with engine off and on then the alt is not charging. Check the blue/brown wire at terminal # 1 of the alt with the key on, you should have power present there with the key on because thats what tells the alt to start charging (excites the field) terminal #2 should have power all the time because it is jumped to the batt post on the alt. Post back your results.

[thebeast61]

ok at the battery i get about 12 volts both running and not running.
I get nothing at the blue/brown wire. i checked at both connections and nothing. I checked with the motor running and with the motor off and the key on.
I get 12 volts at terminal 2 as well.

[fixit-p]

Originally Posted by thebeast61

ok at the battery i get about 12 volts both running and not running.
I get nothing at the blue/brown wire. i checked at both connections and nothing. I checked with the motor running and with the motor off and the key on.
I get 12 volts at terminal 2 as well.

That's the problem right there. Earlier you said you have the gen light in the dash, I'm going to guess that it is not coming on with the key on. Check to see if the bulb is burned out, that would prevent the alternator from working.

[thebeast61]

ok ill check but im not sure it worked before. I never noticed

[thebeast61]

none of the cluster lights work. they havent worked as long as ive had the truck. i havent had a chance to search for the problem.

[fixit-p]

The generator would work w/o the light but the alternator needs an ignition source through a resistor to terminal 1 for it to work. This is done buy going through the bulb or you could wire it from and ignition source and use a 10 ohm 6 watt resistor which you can buy at radio shack. The resistance is very important to have so don't skip it.

[thebeast61]

ok thanks. so i guess i need to do some investigating into the wiring to the cluster then. The bulb is ok so there must be a wiring issue at the cluster.

[thebeast61]

How exactly would i put in a resistor cause i dont have time right now to search out the problem but i need my truck on the road.

[fixit-p]

It's pretty simple, off of the ignition switch there should be a pink wire which supplies the entire trucks ignition circuit (including fuel gauge, gen light, temp light etc..) just tap into this pink wire and and run it to terminal #1 on the alt then cut the wire where it's easy to work and install a resistor. You can solder or use butt connectors to attach the resistor (solder is best) but either way use some heat shrink tubing to protect it from short circuit. So you end up with one end of the wire attached to the pink wire the other end of that wire would be attached to one end of the resistor then a second wire is attached to the other end of the resistor with the other end of that wire connected to terminal 1 of the alt (that would make the resistor wired in series with the #1 terminal). The resistor will get hot (just like a light bulb will so tie it off loosely.

http://www.radioshack.com/product/in...ductId=2062291

[thebeast61]

ok that sounds easy enough. thank you for all your help. you saved me. i am completely ignorant to electrical. for some reason i just dont understand it. its like trying to learn a whole new language.

[7T2]

Originally Posted by thebeast61

ok that sounds easy enough. thank you for all your help. you saved me. i am completely ignorant to electrical. for some reason i just dont understand it. its like trying to learn a whole new language.

If you're interested in learning more, I would recommend you pick up the book "Basic Auto Electricity" from here:

http://www.watsons-streetworks.com/w...cessories.html

It is very easy to understand, and only $7.95. It is written so simply that even a middle-schooler would probably understand it. It covers a lot of things you will eventually have to deal with on an old car, like charging circuits, relays, etc.

[VetteVet]

Here's a diagram of a 64. It shows the ignition switch and the brown and pink wire and their paths. The connectors go to the cluster gauges and the tell lights. The gen tell light shows the brown and pink wire that feeds the light and the brown wire goes through the firewall connector to the external voltage regulator. In your case it now goes to the alternator no. 1 terminal or it should. This is the wire that I would I would put the resistor in to avoid a voltage drop to the coil and all the other feed circuits that the pink wire supplies. Especially if you run an HEI distributor and even the old coil would not like the extra resistance.





This shows how to wire in the resistor but it is for a CS style alternator which does not matter the resistor goes in the same wire.

http://temp.corvetteforum.net/c3/zma...ternator01.htm

[thebeast61]

Thanks 7T2 that book does look like it could help, ill have to check it out.

very helpful link Vet, its always good for me to actully see how something is done to understand it better.

[thebeast61]

I put the resistor in but im still not getting a reading with the votmeter from the alt.

[VetteVet]

Check the brown wire for voltage with the key on and post what you get. If you don't get any voltage or if it is low the alternator won't charge.

Here is a simplified schematic of the brown wire circuit. If you follow it from the no.1 terminal on the alternator through the firewall block, you will see that it goes back to the key switch to the Acc terminal. When the key is turned on the wire is powered up and feeds the alternator regulator.