coil question - Chevelle Tech
Electrical & Wiring Troubleshooting electrical problems.

 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 12 (permalink) Old Jul 8th, 06, 11:41 PM Thread Starter
Tech Team
 
Join Date: Jan 2001
Location: orlando,florida,usa
Posts: 874
coil question

I had posted yesterday about this in chevelle tech but havent gotten a full answer so i will post here.
I am hooking my coil up and wanted to make sure the wires are going back in the correct places. Does the small condenser ,next to the coil, wire up to the positive? Does the red and yellow harness wire connect to the negative along with the aftermarket green tach wire?
blaster is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old Jul 9th, 06, 12:20 AM
Gold Founding Member
Moderator
 
Join Date: Aug 1998
Location: near Kansas City
Posts: 55,232
Garage
Re: coil question

Year, make, model, type of distributor?

On a points type distributor the yellow wire goes from the starter's "R" terminal to the coil's + terminal.
Should also be a whitish cloth like covered wire on the coil's + terminal
Red wire = ?
Tach connects to the coil's - terminal.
If I remember correctly, the condenser also connects to the coil's + terminal.
Dean is offline  
post #3 of 12 (permalink) Old Jul 9th, 06, 7:31 PM Thread Starter
Tech Team
 
Join Date: Jan 2001
Location: orlando,florida,usa
Posts: 874
Re: coil question

Its a stock points distributer on a 72. Theres a yellow/red wire that has a single connector on it. Wasnt sure if its - or +
blaster is offline  
post #4 of 12 (permalink) Old Jul 9th, 06, 9:12 PM
Gold Founding Member
Moderator
 
Join Date: Aug 1998
Location: near Kansas City
Posts: 55,232
Garage
Re: coil question

The only thing on the - side of the coil is the trigger wire from the points and the tach wire.
I still don't remember the condenser wire
Dean is offline  
post #5 of 12 (permalink) Old Jul 9th, 06, 11:17 PM
Tech Team
 
Join Date: Nov 1998
Location: mexico,N.Y.U.S.A.
Posts: 158
Re: coil question

That little codenser you are talking about is just for radio interference its screwed on with one of the coil bracket nuts
steve 72 is offline  
post #6 of 12 (permalink) Old Jul 10th, 06, 12:30 AM Thread Starter
Tech Team
 
Join Date: Jan 2001
Location: orlando,florida,usa
Posts: 874
Re: coil question

ok...im really confused now. I just dont want to connect everything wrong.Is the trigger wire from the points a double red/yellow wire? This red/yellow wire is connected to - or +? The little cylinder condenser(radio interference?) is actually connected to the coil bracket and the wire and connector is only long enough to connect to the - or + of the coil.
blaster is offline  
post #7 of 12 (permalink) Old Jul 10th, 06, 1:41 AM
Gold Founding Member
Moderator
 
Join Date: Aug 1998
Location: near Kansas City
Posts: 55,232
Garage
Re: coil question

Just leave the condenser disconnected for now although I doubt it would really matter which side of the coil it gets connected to.
I belive the trigger wire from the points is black but anyway you can see it's the wire coming out of the distributor.

I don't see any red/yellow wire on the diagram.
http://elcaminocentral.com/articles/wiring/742.gif
Dean is offline  
post #8 of 12 (permalink) Old Jul 10th, 06, 7:51 PM Thread Starter
Tech Team
 
Join Date: Jan 2001
Location: orlando,florida,usa
Posts: 874
Re: coil question

i traced the double red/yellow wire and it seems to go to the starter so i imagine this hooks up to the +side of the coil?
blaster is offline  
post #9 of 12 (permalink) Old Jul 10th, 06, 11:35 PM
Gold Founding Member
Moderator
 
Join Date: Aug 1998
Location: near Kansas City
Posts: 55,232
Garage
Re: coil question

Must be the yellow bypass wire I was talking about then.
Dean is offline  
post #10 of 12 (permalink) Old Jul 11th, 06, 3:22 AM
Lifetime Premium Member
Bill
 
Join Date: Oct 2001
Location: Jay, OK
Posts: 4,012
Re: coil question

There is a single wire coming out of the side of your distributor housing. Connect that wire to the negative side of the coil. The double wire goes to the positive side of the coil.

The double wire is comprised of two wires. One is from the outer terminal on the starter solenoid, and gives the + coil full battery voltage when your ignition key is in the "Start" position. The other wire piggybacked on the same terminal lug is the "ballast resistor wire" and it is energized when the ignition key is in the "run" position. Its function is to supply the + coil with 8/9ish volts at all times while the engine is running. Basically the resistor wire is a carbon core wire of a known resistance value. Much like your present day spark plug wires.

The breaker points will burn up quickly if they are run at 12 volts. The reason being that at 12 volts there is a pretty powerful spark at the point that the points open. Hence the "Ballast Resistor Wire" to step voltage down to an acceptable value.

Even with the "Ballast Resistor Wire" there is still a spark when the points open and absorbing that spark is the job of the "condenser" which is attached to the breaker plate inside your distributor. If you ever lose spark and everything looks perfect then you probably have a bad condenser. Those things have fooled many a mechanic.

When they fail they usually fail to ground and all of your ignition current is permanently grounded until you replace the pesky thing. They prevent that field collapse that gives you your powerful secondary spark voltage.

The telltale symptom of a bad condenser is when you put a test light on the negative side of the coil and crank your engine. If you get a steady light that means the current flow is NOT being interrupted any more by the breaker points opening and closing , rather its going straight to ground through the faulty condenser.

What Dean and others are calling a "trigger" wire (Black) is actually a ground wire which completes the electrical circuit from the ignition switch through the PRIMARY side of the coil to the breaker points. When the points are closed you are saturating the primary winding in your coil with electromagnetic flux.

At the instant that the breaker points open the flux lines collapse across the SECONDARY windings in the coil and induce the high voltage , low amperage current that fires across your spark plug gap.

The "Condenser" you refer to on the outside of the coil is wired to the negative side of the coil. Its there for RFI (Radio Frequency Interference)suppression.

If anyone is interested in seeing all of this stuff about coils feel free to acquire an old coil at the local junk yard and take it apart. Interesting stuff to be found inside. Did you know that they are full of oil? Yuppers. Helps em stay cool. Of course I am referring to stock GM type coils.

Sorry...didn't mean to rattle on but you know how I get late at night. Is the moon full?
charbilly2001 is offline  
post #11 of 12 (permalink) Old Jul 11th, 06, 12:48 PM Thread Starter
Tech Team
 
Join Date: Jan 2001
Location: orlando,florida,usa
Posts: 874
Re: coil question

Thanks Charbilly. Now i can rest easy knowing im going to wire this thing right. One thing i was concerned about was how do i know the difference between a "condenser" and an "rfi"? I put on all new parts but im afraid the parts guy might have given me a condenser instead of an rfi. I compared it to the condenser in the distributer and it looks the samebut is longer and has a blue wire but has the same end as a condenser.
blaster is offline  
post #12 of 12 (permalink) Old Jul 11th, 06, 7:40 PM
Lifetime Premium Member
Bill
 
Join Date: Oct 2001
Location: Jay, OK
Posts: 4,012
Re: coil question

blaster, Forget RFI..that stands for "Radio Frequency Interference" . Its what your ignition system makes while its doing its job. You only know about it when you hear it as static on your radio.

GM's fix for RFI is to fasten a "noise suppressor" to the negative side of the coil. The term "noise suppressor" is basically synonymous with "condenser".

The "noise suppressor" captures the electrical impulses emanating from your coil that your radio sees as static such that you don't hear them coming out of your speaker(s). These impulses occur as induced current from the constant building and collapsing of electro magnetic fields acting upon the wiring of the ignition circuit.

The noise supressor is filled with a coil of paper onto which a conductive substance is afixed. That coil of paper is designed to "bleed" those electrical impulses to ground over time without interrupting the ignition current.

If you want to see this RFI at its extreme take a look at the older Corvettes with their metal shielded spark plug wires. Those Fiberglass bodies were rotten at shielding RFI from the radios in those cars.
charbilly2001 is offline  
Sponsored Links
Advertisement
 
Reply
Gear in this thread - Powered by O'Reilly Auto Parts

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
wires to coil? HD-DYNA Electrical & Wiring 2 Jul 27th, 05 10:47 PM
Coil charge time vs type of wires used, long. SS4speed Performance 8 May 15th, 05 7:23 PM
Unilite Distributor, and coil wiring chuck240z Electrical & Wiring 4 Mar 17th, 05 6:38 PM
Coil Problem - Points style elcamino72 Engine 2 Aug 24th, 04 8:51 AM
Ballast Resistance and Jacobs Coil Twilightoptics Electrical & Wiring 1 Jun 30th, 03 4:10 PM

Posting Rules  
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome