Ignition and Coil Wiring

[kevin_tbird]

I know that my coil is not properly connected, but I am confused by the many different wiring diagrams I have. We are working on a 1960 tbird.

I am using reproduction wiring harnesses that matched the orig. harnesses. With one exception; the pink resister wire is replaced with a pink non-resister wire. Please note that I do not have an overdrive solenoid - I am working with a 352 and Cruise-o-matic.

When attempting to start the engine I do not have a spark.

At the coil I have a black wire connected to the neg side of the battery that comes from the distributor. I have a red/green wire that runs back to the firewall. At the firewall the red/green is joined by a brown wire that comes from the starter solenoid and both connect to a pink wire that runs through the firewall.

There is a pink wire connected to the ignition switch.I have not yet check for continuity to the pink wire at the firewall; however I assuming is is the same until I can ohm the wire. I am not sure it is connected to the correct post. Does anyone have a picture of the back of the ignition switch that shows where the pink wire should connect?

I've added a diagram modified to show how my wiring attaches.

Thanks for you help. Maybe I can fire her up this weekend.

Kevin

[cdhowell]

Do you have Power on the pink wire when the key is on?

Yes : check coil, points, condensor, and ground connection.
No : Get power on the pink wire.

[kevin_tbird]

I do have power at the pink wire with the key in the on position and I have no voltage with the key in the off position.

I have connected a timing light to the distributor primary wire and am not reading a signal.

What should I test next?

Kevin

Here are some photo's of the wiring setup.

[YellowRose]

Ignition and Coil Wiring

Kevin, I dug up my spare ignition switch in hopes of being able to tell you where that Pink wire goes. The schematic shows that it goes to the C post, along with a Black-Green wire. So, according to the schematic, you should have one of the posts with a Black-Green wire on it along with the Pink resistor wire. On one of the other postsThe posts in the schematic (see below) show a C, A, B and S post, with the center post being the starter connection I gather. On my ignition switch the center post on the raised ceramic is labeled ST which I assume has to mean Starter. Then there is an ACC post, a BAT post and IGN post. I figure B has to be the Battery connection. It has a Blue-Red and a Yellow wire on it with a lamp symbol. A is maybe the Accessory post, and that would leave IGN to be the C post. But someone needs to confirm that. The S post has a Red-Blue wire on it, and the A post has four wires on it! 2 black wires, a Black-Green, and an Orange-Yellow wire.

[simplyconnected]

...Yes : check coil, points, condensor, and ground connection...

I can't agree more. If you don't have a good ground on your distributor, you will NOT get a spark.

Also, if your condensor is bad you won't get a spark. I have had problems here in the past. Sometimes they short to ground which bypasses the points and renders them useless.
See bottom illustration:
Pull on your distributor wire (12216), check for internal broken wires, good connections, and make sure your ground wire (12264) screws are tight.

You show pictures of splices in the middle of your wires. My preference is to lug and crimp all wires and tightly connect them under a screw (or nut). Ring terminals work best because they can always be reconnected. If you have several wires to connect, a longer screw and a few washers work well. I tape the first cigarette-lap backwards (so the splices don't get all gooped-up and black), then turn the tape over and continue back with the glue on the bottom.

Check your coil. Turn it upside down and look for the words, 'Int Res'. If it has internal resistance, use a straight wire from your IGN terminal. If it has no internal res., use the Pink wire OR a firewall resistor.

Even though Coils are oil-filled, they get hot and sometimes open. You can use your Ohm meter to check the primary windings. Polarity is VERY important. (+) means towards the key switch or starter solenoid. Examine this very simplistic diagram:

Because BOTH primary and secondary are common to GND, if you get the primary wires backwards (I've seen it many times), your coil output voltage won't be as high.

The wire coming from your starter solenoid is only there to cut out any resistance and give full +12-volts to the coil while the starter is engaged. This also brings up a point... if you use a 'test' pushbutton to bump the engine, your ignition is hot and plugs will fire as long as the solenoid is energized.

I hope this helps. - Dave

[tbird430]

I wonder if starting the car with a non-resistor ignition wire to, what appears to be an all STOCK ignition system, fried something.

-Jon in TX.

[cdhowell]

Pull the coil wire off the dist. side and hold it about an 1/8 inch from a good ground. Watch for spark when cranking. If you have it there then it is a distributor problem. Wish I had a nickle for every time I put a cap on and forgot the rotor. Save the timing light for timing and use a meter to trouble shoot.

[kevin_tbird]

Dave

As background this engine was rebuilt about 5 years ago, broken in on a stand, fogged and put away. I just installed it in the vehicle. The wiring harness is a new reproduction wiring harness.

I've ohm'ed the coil 11,200 and 1.5k. Seems to be good. It is a repro yellow top coil from one of the vendors so I assume no internal resister. My pink wire is NOT a resister wire. However, the lack of a resister should not be a problem for starting/testing the vehicle - right? There are lots of threads on the site that say so.

Distributor was rebuilt when the engine was rebuilt. I have full battery voltage at the + side of the coil. The battery voltage is flowing from the ignition switch. When cranking the voltage drops about 6v which is within spec.

After disconnected the pink wire the brown wire from the starter solenoid does NOT carry battery voltage to the coil. When cranking the engine it generates a little more than 2v. After cranking the voltage drops slowly. I'm not sure how far, but down to at least 0.5v for certain. (maybe the condenser bleeding down?).

Shouldn't the starter solenoid/switch provide battery voltage to the coil?

The points inside the distributor are clean and opening and closing freely. The internal ground wires in the distributor have continuity to the block. The wire from the distributor to the coil has continuity and is in good shape. And yep, the rotor is there.

I'm not seeing a distributor or coil problem, unless the condenser is bad. Can I check that somehow?

I HAVE COME TO BELIEVE that I am not getting a signal from the distributor, which I believe means that the points are not closing. I connected an old sears engine analyzer to the dist side of the coil and when the key is turned to run it buried the scale to the right (points open 3.2v+). No amount of bumping the engine along ever moves it off the open. When the key is off it is buried to the left (0v).


PS. There is only one splice at the firewall and it is a factory correct splice. No problem at that point.

[simplyconnected]

As background this engine was... broken in on a stand,

Piston ring break-in can only be accomplished while the engine is UNDER A LOAD.

...However, the lack of a resister should not be a problem for starting/testing the vehicle - right?

That's right. Some racers NEVER use the resistor. It just means the points will need to be changed more frequently because they dump more current. At high engine speed, the coil never gets enough time to completely fill, anyway.

I have full battery voltage at the + side of the coil... When cranking the voltage drops about 6v which is within spec.

The ONLY reason your voltage should drop is because your battery is weak and it is dropping half its voltage.

After disconnected the pink wire the brown wire from the starter solenoid does NOT carry battery voltage to the coil. When cranking the engine it generates a little more than 2v. After cranking the voltage drops slowly. I'm not sure how far, but down to at least 0.5v for certain. (maybe the condenser bleeding down?).

This is a problem. When the solenoid is energized, you should get full battery voltage to the distributor wire post. This wire bypasses any resistance wire going to your coil. When cranking your engine, that post should show full battery voltage to GND.

Shouldn't the starter solenoid/switch provide battery voltage to the coil?

Yep, FULL voltage.

...I'm not seeing a distributor or coil problem, unless the condenser is bad. Can I check that somehow?

Sure! Your condenser is just like any capacitor, but it has a very high voltage rating. Simply put, you can put it in your hand, fill it with a 9-volt battery, and see how long it holds a charge. Use your volt meter. You can also use a resistor in series with the 9-v battery, and see how long it takes to completely fill. If it doesn't hold any charge, it is shorted internally.

I HAVE COME TO BELIEVE that I am not getting a signal from the distributor, which I believe means that the points are not closing. I connected an old sears engine analyzer to the dist side of the coil and when the key is turned to run it buried the scale to the right (points open 3.2v+). No amount of bumping the engine along ever moves it off the open. When the key is off it is buried to the left (0v)...

Now we're getting somewhere. Your distributor only DUMPS power to ground. Again, if your ground is missing, it can't complete the circuit. OR, if your points are shorted, the coil can't saturate. Set the distributor cap aside.

Pull your distributor wire off the coil and check the wire to ground while you crank the engine. Use your Ohm scale on 200-ohms (or something low). You should see the points open and close. (You can use a continuity tester for this, too.) If you don't see open-close, fix the distributor wiring.

Using the coil, you can make a spark by pulling the coil wire off and temporarilly replace it with a spark plug wire, with the plug resting on the engine block. Then, ground the D post on your coil. Your spark plug should fire. Moving downstream, ground the open points, your spark plug should fire.

Let's keep talking about grounds...
Is your coil properly grounded?
Is your point set insulated where the wires attach?

[kevin_tbird]

regarding "Piston ring break-in can only be accomplished while the engine is UNDER A LOAD."

I had the transmission attached to the engine on the stand and in gear. No resistance on the output shaft though.

The battery is new and the ignition switch is new. The voltage drop I was describing was a voltage drop across the ignition switch at the end of the pink wire [disconnected from the r/g and brown wires] during cranking. I thought dropping up to 6.6v is normal misreading step 4 of the primary circuit resistance test in the shop manual (pg 2-3). We will come back to this after we get a complete ciruit.

I am a bit embarrassed to admit this but I jumped right to the last step of that test procedure. Starting over with ign switch on:

• Voltage drop battery to dist B post is 0.64v

• Disconnected the bullet connector and the voltage drop across the ignition switch circuit is .2v. [battery to end of pink wire]
• With the bullet connector still disconnected the voltage drop across the starter solenoid is 12.9v with battery voltage of 13.1v. [confirming minimal voltage from solenoid]

Voltage from the solenoid seems to be a problem. Can you look at the picture again - is my wiring correct? This seems to be the problem area. I want to be sure I understand your note. The full battery voltage should be measured between the battery post of the coil and [engine block] ground. Right? This is where I am only getting about .2v. Can I bypass the solenoid with a jumper from the battery and see if this solves my problem? Hang -on that means I would be unable to turn off the car using the key if I did that - right?

The coil ground measurements are interesting. I tested voltage drop with ign on and points closed and found a .12v drop between the coil - post and engine ground, breaker arm, breaker plate, dist body]. Interestingly enough I left the a meter connected and when I glanced back at it the needle was moving. I don't think the points are closing tightly. After sitting 5 years maybe the grease has hardened up. I'll look at that tonight and test the condenser.

Kevin

[simplyconnected]

Kevin, I know your car has a starter relay with four posts. Some cars only used three posts. That means they did not bypass the ballast resistor that feeds the coil. So, is this absolutely necessary? No. It's only meant to help battery voltage drop during cranking. The truth is, your engine should start with either a resistance wire (or ballast resistor) OR a straight wire coming off the ACC side of your key sw.

Your problems run deeper. You said you have battery voltage at the coil. That's what you need.

You also said your distributor wire isn't opening/grounding with the points. Start there. With the D (primary) wire removed from the coil, put your meter on that wire, the other prod on engine GND, and set it to OHMs. Crank your engine. If the points never close (or never open) you will see no meter movement as the distributor turns. That's a problem you need to address first.

For points lubrication, I use a thin coat of Shell moly grease. This green stuff never hardens and when you pull it apart in your fingers, it 'strings' real long. That means it's moving around.

Good luck in your tests.

[63-4drpost]

points

take some fine sand paper, fold it over, and put it between the contacts on the points. doesn't take much. then clean the contact faces with a folded dollar bill. Most point have been laying around for years, buid up a coating on them that will not pass current. give it a try. If you are tired of **** points, do like I am doing and convert to Duraspark 2 ignition.

[Guest]

I would go with Pertronnix ignition system! I replaced "Christine's" and have had no more trouble! Keep you a GOOD set of points on habd
Richard D. Hord

[kevin_tbird]

Many thanks to redstangbob who walked me through the diagnostic procedure on the ignition wiring on the phone.

I can't tell you exactly what was wrong with the car, last night I cleaned the points and moved them back and forth several times and then went through the entire wiring one step at a time. At the end she fired right up.

I still think I have a wiring problem at the ignition switch and will check that thoroughly next week.

Kevin

[lawyercalif]

I went with the Petronix it was easy to install and works great.