Starter wiring issues...

[studeclunker]

Sheeze, sorry about the H-U-G-E pics!

Does anyone know if a new wiring harness for the ignition and starter is available anywhere? I can find anything but.

[geezer#99]

Maybe easier and cheaper to eliminate the yellow wire and the resistor wire.
Put in an hei distributor that only needs a dedicated 12v.

[studeclunker]

Does anyone know where I can get a wiring harness for the ignition-starter circuits? It appears they have a modular plug on the firewall and these along with the sending wire for temp are all that's in that one. I can find the headlamp loom, for the lights in the hood and for the rest of the engine electrical. But not that one.

[studeclunker]

Originally Posted by geezer#99

Maybe easier and cheaper to eliminate the yellow wire and the resistor wire.
Put in an hei distributor that only needs a dedicated 12v.

Sorry, HEI distributor?

[geezer#99]

High energy ignition.
Like this.

https://www.ebay.com/itm/SBC-Small-B...UAAOSwA~VaA6A5

[studeclunker]

"Professional installation is highly recommended. Instructions are NOT included.

It is your responsibility to purchase the correct part. "

Ah... I'm not too sure about this. Replacing a distributor would require some help. I'll have to ask a few friends. This looks to be a great idea and not even very expensive. It's just doing it right the first time.

[rpmerf]

Engine harnesses, if you want to go that route.

Classic Parts:
https://www.classicparts.com/Wiring-.../products/287/

Brothers Truck:
https://www.brotherstrucks.com/Engin...products/2108/

GMC Paul:
https://gmcpauls.com/wireharness_2.htm

[studeclunker]

Well... I rebuilt the wiring harness in an exact duplicate to the original with the exception to the purple wire. I had to run an ordinary wire. However I have purchased an external resistor for the coil.

Turns out the coil wire from the R terminal on the Starter was broken. Hence the reason I had no spark. I still don't get why it was firing when the starter was going. But then, refer back to my opening comments, I'm a mechanical ignoramus.

So all new wires from the firewall down to the starter and a whole new dance! Now when I turn on the key (just on, not to start), the Starter engages and won't stop!

WTF???

Which wire have I swapped this time?

Help please?

[rpmerf]

Check where your coil and signal wires are going on the starter. There should be 2 or 3 studs you can connect to on the starter. If you connect the coil wire to the signal stud, it will do what you have described.

[studeclunker]

Originally Posted by rpmerf

Check where your coil and signal wires are going on the starter. There should be 2 or 3 studs you can connect to on the starter. If you connect the coil wire to the signal stud, it will do what you have described.

Signal Stud? Is that the S terminal? I have the purple wire on the S terminal but the black (coil) wire on the R terminal. Should I have the purple wire on the R terminal as well?

In this picture, the purple wire is in the S terminal at the top of the picture. The R terminal is below.

Actually, this is a 'before' pic because we are having trouble with the camera again and I can't download pics from it... again. The wires though, are all in the same positions.

[rpmerf]

I can't see pictures, I'm at work.

Starter signal wire (purple) goes the S, and the coil wire (purple/orange) goes to R. Sounds like you have it right. Might want to pull the wires off and make sure purple is only hot when the key is turned to START. If not, trace it back.

I rebuilt the wiring harness in an exact duplicate to the original with the exception to the purple wire. I had to run an ordinary wire. However I have purchased an external resistor for the coil.

I'm wondering if this is where some of the confusion is coming from. According to the schematic I have, there is a purple wire for the starter signal, and an orange / purple wire for the coil. The coil wire looks like a cloth covered wire on my truck. You may need to trace it back to the bulkhead to determine the right wire is going to the right place. You will also need to verify that each wire is getting voltage at the right time. Purple should only get voltage when the key is turned to start. Purple / Orange gets voltage when the key is in the start or on position.

[studeclunker]

Thank you, that diagram clears up a lot for me. Okay, then I should possibly have two wires at R and one at S.

I also found this diagram for a '64 chevy C-10 showing the white, orange, purple wire going direct to the coil.



Confusion, ain't it fun?

[studeclunker]

Okay, the white, orange, purple wire and yellow are on R. The purple is on S. I have six volts to the coil and nothing happens when I turn the key to start.

So, I suppose it's time to figure out why no power to the... Purple wire, I guess?

[rpmerf]

Sounds like your wires are set up correctly.

Neutral safety switch on the top of the column can cause the starter to not get power. Also the ignition switch.

[studeclunker]

Working backwards from the greatest possibilities, ie: I screwed something up, I started carefully examining everything I did. When splicing the wires, two of them were so bad, I spliced them right up against the blade in the modular plug through the firewall. This required pulling them out, splicing the wire and reinserting them. The purple wire was in the wrong position. Put it back in the right position and the truck fired right up. The coil is still getting twelve volts even though I'm running the wire through an external resistor. It shows six before I start the motor and twelve after starting. But at least the truck starts and runs now.

THANK YOU EVERY-ONE who signed on here to help! I checked your suggestions and greatly appreciated your taking the time to help!

[geezer#99]

It runs!
Not for long though!
Points will burn out and coil will too if you don’t reduce that 12v running voltage.

[studeclunker]

t

Originally Posted by geezer#99

It runs!
Not for long though!
Points will burn out and coil will too if you don’t reduce that 12v running voltage.

Yes, well that's why I bought the external resistor (that doesn't seem to be working). Leave it to NAPA.

It's kind of odd though. With the switch on and engine off, the voltage at the coil shows around six or seven volts. Once I start the motor, it jumps up to twelve to fourteen.

[geezer#99]

Maybe you have it wired wrong.
Or it’s not rated for what you need.
Post a pic of it.

[studeclunker]

Originally Posted by geezer#99

Maybe you have it wired wrong.
Or it’s not rated for what you need.
Post a pic of it.

Me? Wire it wrong?
Well, okay here goes a try on the pics.




By the by, I switched the wires just in case I had it backwards. Doesn't work any better either way.

[geezer#99]

Looks normal.
What happened to the original resistor wire?

[studeclunker]

The original resistor wire was missing half it's insulation jacket. Along with the rest of the wires in that harness. Can this kind of wire be procured?

Okay, I've found an answer to my question at O'Reilly's. I guess I'll order the wire and replace the one currently running to the coil.

[geezer#99]

Wrap it with black tape and use it.

[studeclunker]

I found a wiring harness for this application!

In case anyone else needs one, it's located here at Tucker's Classic Auto Parts:

https://www.tuckersparts.com/Engine-...-WEN-6310.html

[studeclunker]

Well it turns out Tucker's gets their wiring harnesses from American Autowire. The harness for this application is part number 30830. It was $88.30 total. All the same as original right down to the fabric covered wire and purple resistor wire. It was a touch short and I had to run the wire straight up in lieu of along the firewall like the original.

Now to get some great big vintage trailers moved!