The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 06-22-2009, 10:40 AM   #1
mlsprouse
Registered User
 
Join Date: Sep 2007
Location: san antonio tx
Posts: 11
Need advice with ignition wiring

Im still at it had a fuel leak to fix got that out of the way now i need to know if the wire coming from the positive side of the coil is supposed to be wired into the the wire going to the r side of the solenoid on the starter. The diagram in the haynes manual shows two purple wires coming out of the firewall i only have one. The other wire is red. The way i have mine is i ran a wire from the positive side of the coil to the r side of the solenoid then ran the purple wire coming off the firewall to the s side of the solenoid on the starter. Also i want to know does it matter where you stab the distrubutor as long as its pointing to number one and you go in firing order. I brought it up to tdc number one my son said it pushed his thumb off i lined the rotor up with the number one plug on the dist and went in firing order with the rest of the plug wires is this correct? Im just trying at this point to eliminate what is not wrong so i can concentrate on what is. Thanks for your help.
mlsprouse is offline   Reply With Quote
Old 06-22-2009, 05:39 PM   #2
El Jay
Gone to greener pastures
 
Join Date: May 2007
Location: Gateway to the Delta
Posts: 7,354
Re: Need advice with ignition wiring

When your ignition key is in the "start" position, it bypasses the resistance wire from the ignition switch so you are feeding a full, straight 12 volts from the solenoid to get the engine to fire easier.
When the switch is turned back to "run" the solenoid wire is disconnected and the resistance wire from the ignition switch is feeding the coil.

You are correct on the plug wires.
If you're not real familiar with doing that stuff, 1 wire at a time is the best way to go.
If you have an aftermarket manifold & the firing order isn't cast on it: 1-8-4-3-6-5-7-2.
__________________
'69 Chevy 1/2 T LWB Stepper: Daily Beater
'72 GMC 3/4 T Fleet: Another Daily Beater
'72 Plymouth Gran Coupe: ?


"Ah women. They make the highs higher and the lows more frequent." Friedrich Nietzsche

"Never kick a fresh turd on a hot day." Harry S. Truman

GUN CONTROL: Never having to say, "I missed you."

Always fire two warning shots into your attacker's chest area before putting a bullet between his eyes. Paraphrased from Louis Awerbuck
El Jay is offline   Reply With Quote
Old 06-22-2009, 05:53 PM   #3
fixit-p
Registered User
 
fixit-p's Avatar
 
Join Date: Dec 2008
Location: Yay Area CA
Posts: 2,329
Re: Need advice with ignition wiring

What year truck do you have? In the electrical section there is a sticky on wiring diagrams heres the link http://67-72chevytrucks.com/vboard/s...d.php?t=185856 post # 104 has some links to download some high res. copies in pdf format.
fixit-p is offline   Reply With Quote
Old 06-23-2009, 07:29 AM   #4
mlsprouse
Registered User
 
Join Date: Sep 2007
Location: san antonio tx
Posts: 11
Re: Need advice with ignition wiring

ok but im still not clear on if i have the wires hooked up corretly .do i need to splice the wire coming off the coil into the purple wire going to the solenoid . the diagram in the manual is confusing. like i said i ran a wire from the positive side of the coil down to the r side of the solenoid then i ran the purple wire to the s side of the solenoid is this correct? i did the wires one at a time lined up the rotor at number 1 and went in firing order in the direction it stated in the manual. im just not sure if i have my ignition wires right if i do then maybe the points are off a little. or the engine was not time right from the motor supply but as methodical as i have been with this project i would know to check for that ,but ive slept and drank alot of beer since that stage.

Last edited by mlsprouse; 06-23-2009 at 07:33 AM. Reason: wrote in wrong part
mlsprouse is offline   Reply With Quote
Old 06-23-2009, 08:25 AM   #5
Tx Firefighter
Watch out for your cornhole !
 
Tx Firefighter's Avatar
 
Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
Re: Need advice with ignition wiring

No, do not splice into the purple wire. That is the signal wire to engage the starter. You are correct, in that you have the wire from the "R" terminal of the starter to the positive of the coil. That feeds a full 12v to the coil while cranking the engine.
__________________
I'm on the Instagram- @Gearhead_Kevin
Tx Firefighter is offline   Reply With Quote
Old 06-23-2009, 08:51 AM   #6
mlsprouse
Registered User
 
Join Date: Sep 2007
Location: san antonio tx
Posts: 11
Re: Need advice with ignition wiring

ok so then the other wires have to be correct .so i guess my next step is to check the point gap. now the wire coming off of the distributor i have going to the negative side of the coil and the wire that is on the condensor on my coil bracket i have going to the positive side of the coil if this is correct then like i said the only thing left is my point gap. please let me know if i am right on the dist wiring.thanks for your help firefighter.

everyone else is running out, your running in, thanks for what you do!
mlsprouse is offline   Reply With Quote
Old 06-23-2009, 09:18 AM   #7
Tx Firefighter
Watch out for your cornhole !
 
Tx Firefighter's Avatar
 
Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
Re: Need advice with ignition wiring

You've got the wiring right.

Do you have a test light ?

Here is an easy way to check your points...Hook your test light clip to a good ground. Then, touch the tip of the test light to the negative side of the coil (where the little distributor wire is screwed on). While cranking the engine, the test light should flash.
__________________
I'm on the Instagram- @Gearhead_Kevin
Tx Firefighter is offline   Reply With Quote
Old 06-23-2009, 09:28 AM   #8
mlsprouse
Registered User
 
Join Date: Sep 2007
Location: san antonio tx
Posts: 11
Re: Need advice with ignition wiring

ok thanks for your help!
mlsprouse is offline   Reply With Quote
Old 06-23-2009, 09:41 AM   #9
fixit-p
Registered User
 
fixit-p's Avatar
 
Join Date: Dec 2008
Location: Yay Area CA
Posts: 2,329
Re: Need advice with ignition wiring

You still need to run your resitor wire to the R terminal with the coil wire it should be white/orange/purple I beleive. If the orig resistor wire was replaced with the red wire you'll need to use an external resistor unless your coil has an internal resitor (not original) Hres a low res diagram
Attached Images
 
fixit-p is offline   Reply With Quote
Old 06-23-2009, 09:50 AM   #10
mlsprouse
Registered User
 
Join Date: Sep 2007
Location: san antonio tx
Posts: 11
Re: Need advice with ignition wiring

so your saying the red wire needs to go to the r terminal on the solenoid with the yellow wire?
mlsprouse is offline   Reply With Quote
Old 06-23-2009, 11:03 AM   #11
VetteVet
Msgt USAF Ret

 
VetteVet's Avatar
 
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,718
Re: Need advice with ignition wiring

installing the distributor is pretty simple and it can be placed at any point on the rotation
Your question about the install, while it is possible to make the engine run, is not the best way to go about it. The distributor should be installed in the factory position in order to maintain the firing order and be able to adjust the timing. The vacuum advance canister may not allow the distributor to turn enough for proper timing without hitting the intake manifold or the coil mounting or the oil pressure sender. I have found that having the vacuum canister at a 45* angle to the intake with no. one spark plug wire at the right front of the cap looking from the front, works best.

The easiest way to do this is to do the thumb check as you have and then place the line on the damper with the zero mark on the timing cover, then drop the distributor with the rotor lined up as I stated. The oil pump shaft may prevent this but I assume you know how to overcome that.

I hope you have a v-8 engine as that is what I have referred to. It really helps to identify the year of your vehicle and give some details like engine type, standard or auto trans, you get the idea. Make a signature like the other guys and you won't have to type it all out on every post you make.

Here is a very good site on the points ignition system (http://abbysenior.com/mechanics/ignition.htm). You need to wire the coil with the two feed wires on the positive terminal and the distributor and the capacitor on the negative side. The capacitor helps to smooth out the voltage surges when the coil magnetic field collapses. It also cancels out radio static.

Check the stickys in the electric forum like FixitP said They are really helpful.
__________________
VetteVet

metallic green 67 stepside
74 corvette convertible
1965 Harley sportster
1995 Harley wide glide

Growing old is hell, but it beats the alternative.
VetteVet is offline   Reply With Quote
Old 06-23-2009, 11:08 AM   #12
fixit-p
Registered User
 
fixit-p's Avatar
 
Join Date: Dec 2008
Location: Yay Area CA
Posts: 2,329
Re: Need advice with ignition wiring

Quote:
Originally Posted by mlsprouse View Post
so your saying the red wire needs to go to the r terminal on the solenoid with the yellow wire?
You'll have to determine that. The original wire had a built in resistance to limit the coil voltage to ~9 volts with the engine running the reason for wiring into the starters R terminal is to bypass the resistor and provide full battery voltage only while cranking (as stated by tx and el j). Trace the red wire and see if the po had replaced the resistor wire with it, if yes you'll need to determine if you need to install a resistor or not (check the coil to see if it has internal resistance) and the voltage at that wire. I put an arrow pointing to the resistor wire below trace it back to the bulkhead and see which wire is there.

Also in my first post there is a link where you can download these diagrams in high resolution the pdf files are to large to attach to a thread.
Attached Images
 
fixit-p is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:18 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com