No Fire from coil

Keeper79

Keeper79

Member
Afternoon, new to the site but have enjoyed reading lots of threads..

Currently working on my father in laws '29 Roadster that has been sitting for over 3 yrs. Yeah, trust me I do my best to make him feel bad for neglecting it.

Rebuilt the carb, drained fluids, refilled, new plugs in and gapped, points gapped, new battery and lots of cleaning later.

Last weekend I attempted to get it to fire up. Found to have no fire coming from the coil. Got another coil and same thing. There is power going to the box, but nothing is coming from the coil. Checked the coil wire and its good.

I can work a voltmeter and rebuild mechanical stuff but electical trouble shooting is certainly a weakness. Any tips would be greatly appreciated.

Don't know if this has anything to do with it, but was wondering when is the cut out switch on the generator suppose to close? Is it suppose to close when the electrical switch is turned on, when you hit the starter, or when the engine fires up and makes a certain amount of volts?

Any help would be great, I love working on this car and to hear it fire up to life again would really make my day.

Thanks

Dave
 
Keeper79 said:
There is power going to the box, but nothing is coming from the coil. Checked the coil wire and its good.

I can work a voltmeter and rebuild mechanical stuff but electical trouble shooting is certainly a weakness. Any tips would be greatly appreciated.

Don't know if this has anything to do with it, but was wondering when is the cut out switch on the generator suppose to close? Is it suppose to close when the electrical switch is turned on, when you hit the starter, or when the engine fires up and makes a certain amount of volts?
Click to expand...

There should always be voltage at the negative coil wire (black). There will also be voltage at the positive wire (red) IF the ignition is off OR the points are open. If the key is on and the points are closed and the voltage is still showing on the red wire the points or ign. sw. are not making contact.

The cutout sw. should close when the generator is producing more voltage than the battery. So the answer is "when the engine fires up and makes a certain amount of volts" is the correct one. The generator will act like a motor, and try to spin, when there is 6 volts applied to the armature. The fan belt will keep the gen from spinning and the gen. will run the battery down except the open cutout prevents this.
 
If there is a problem with the points, you won't get a spark from the coil wire. If it has the so called modern points installed there is a good possibility that is where the problem lies. the points on the cutout shouldn't close untill the engine is running and the rpms are increased so the generator begins to charge. If the points in the cut out close and the generator is not charging, it will motor. in other words the generator will try to run like an electric motor, if this happens the generator will get pretty hot and run down the battery and somtimes damage the generator. The generator is not powerful enough to turn the engine so it will get hotter and hotter until it kills the battery.
 
I would file the points first but this is the general advice I give to "I have no spark";

Some possibilities are:
1.Blown or defective fuse or fuse holder
2.Bad connections at ammeter, or ammeter itself (to find out put a jumper wire from one post of the terminal box to the other to take the ammeter out of the circuit temporarily)
3.Bad ignition switch and/or cable, or loose cable connection at switch.
4.Loose or broken wires at bottom of coil
5.Loose or broken wires inside terminal box
6.Loose, bare or broken pigtail wire under distributor plate, or wire grounding to plate or distributor body
7.Points not opening, or point arm grounding to cam due to worn rubbing block
8.Worn electrode in underside of distributor cap
9.Loose or broken high tension wire from coil to cap
10.Condenser burned out or grounding (some condensers are too long and can touch the distributor body inside)
11.Weak coil
12.Rotor not turning due to loose cam screw or bad timing gear
Ok now break out a volt meter (a light bulb can give false readings).
Start at the fuse block, you should have voltage on both sides of the fuse. If you only have voltage on one side, replace the fuse of fuse block.
Now with voltage on both sides of the fuse, move up to the junction box. There should be voltage at both terminals. If voltage is present only on one side the problem is at the ampmeter and you should Jumper the ampmeter for now.
You should have voltage on both sides of the coil. If not, remove the red wire on the coil and check again. If you now have voltage on both sides, you have a problem further on. If the voltage is still only in one side you have a bad coil.
Open the points with a piece of paper and remove the condenser. Turn the key on and you should have voltage at the points. Replace the condenser and you should still have voltage. If voltage is missing, remove the top plate and check for voltage on the bottom plate. Check is the connector from the ignition switch screwed in to far? Do you have voltage on the wire to the upper plate? Is this wire shorting to ground or broken? Are the point closing.

Let us know what you find.
 
Thanks for the help..

So far I have found the ignition switch to be funky. I removed it and tested it on the bench with the voltmeter. As you turn the switch on it will work, but only in a small 5 deg. section of the 90 deg turn the key moves.

I bypassed the switch with a simple toggle switch just to see it that was the problem.. its not.

Do have power on both sides of coil. However there is no spark coming from the coil going to the cap..

going back downstairs now to double check all wires and make sure I didn't miss anything else..

Buddy is suppose to swing by tomorrow to look also. He and his father own their own car shops. So getting another set of eyes and ideas in the mix will be good.

Will check back in..

Thanks again for the help.
 
No expert here, but I concur with Mitch. Funny how much points will corrode in a short time of sitting. And you're talking 3 years. My neighbor is a part time resident and cranks his up when he comes down. " Fired up last year without a problem" . This year no go. I took a file to the points and away she went. Give it a try. Easy things first.
 
First the ign. then the points provide a path to ground. Once grounded the voltage will all be dropped across the coil and the second lead (red) will read zero. The answer is in the points or not making contact to finish the path to ground or an open circuit in the wires. Your getting close now.

Make that four for filing.
 
If you have the modern points filing the contacts probably won't help. I had lots of problems with the modern points, They would cease to function with no visable reason. it would seem to be a short where the pig tail of the condenser connected. If I replaced them they would work for a while and then may quit again while driving down the road just like the switch had been cut off. When this happened on the AA and I had to have it towed that was enough for me. I have been told that NAPA sells good modern points but they sell two different quality sets, the good ones are twenty something dollars. I buy good original style points from Snyder or Bratton for just over ten dollars per set. I now only use original style points. This may not the problem, I just thought it was worth mention. Good luck and keep us posted.
 
Not sure that it's the modern points. I switched to modern and they have worked flawlessly. My experience with ignition parts (points, condensers, coils) is that some of them are bad out of the box - quality control left in the hands of the consumer.

Kindly record me as #5 voting for filing the points - or installing another set!
 
Just for ha-ha's, have you ck'd the wire from coil TO the distributor?? Is the rorotor making contact with the cap??
Paul in CT
 
Thanks for all the great info so far.. going to try and answer all the questions but like I said electrical is a weakness..

So far this morning I started with the points. Gave them a light filing, as well with the distributor contacts for the plugs and also on the inside. Button edge also cleaned up, button is making good contact with the cap..

My brother in law stopped in and we did some checking again and found the points to not be getting the power like earlier mentioned. Found it to be grounding out. So this led to pulling the armored wire from the distributor and the dash. New wire installed and everything back together. Getting good readings now for the points when open and closed. Again not a strong point but my brother in law was happy, and said we got it like its supposed to be.

So now we know we got fire at the points, we got fire at the coil however the coil isn't firing to the distributor. The coil wire going to the distributor is good, continuity is good and shows .02 ohm of resistance.

Right now we are thinking that either the condensor may be bad or grounding out, and we may also have a bad new coil.. Find it hard to be 2 bad new coils in a row but hey stranger things have happened. Stores are closed for the day, and will have to continue later this week.

As for the points being modern or not. I would have to say original style from the looks. Also the distribitor looks to be the same. The button does show signs of being newer and modern.

will need to either fix or order a new ignition switch as that is currently a toggle switch till we figure out the rest.

Dave
 
If you have the modern points the condenser will be on the upper plate under the dist. cap. If it is original the condenser is mounted in the lower housing and you can see the end of the condenser sticking out on the passenger side above the head and manifold. If you have the modern points replace them, this will MORE than likely be the problem. If you choose to use modern points ask for the best or else you may get junk put off on you and there is no return on electrical parts at most Napa or other local parts stores. If the points are original , sometimes you have to file or sand the hell out of them to remove the oxidation. you will then need to set the gap at .018 to .022 I set mine at .022 if you run the original condenser, make sure that the screw that holds the condenser to the housing is tight and that the end hasn't come unsoldered from the condenser. At any rate or whatever points or condenser that is now on your car you can mount the modern style condenser ( Ford V8 1958 through the last year the condenser was used, maybe 1975) on the coil bracket and connect the pig tail to the switch side of the coil. this will be the red wire, unless somebody has rewired it with the incorrect color. If you go this route you will need to remove the present condenser. Good luck, I am sure others will offer advice or help.
 
I have the original version then as the condenser is on the bottom. I did a good job sanding down the points and we set them at .020 this morning.


Dave
 
So now we know we got fire at the points, we got fire at the coil however the coil isn't firing to the distributor. The coil wire going to the distributor is good, continuity is good and shows .02 ohm of resistance.

Right now we are thinking that either the condensor may be bad or grounding out, and we may also have a bad new coil..

Remove condenser, insure the points are closed and there is no voltage at the points with the ing turned on. If you have voltage the points are not closed or the dissy is not grounded.

Place the high voltage wire from the coil to within 1/8" of the head bolt but no more than 1/4". Using a screw driver open the points and you should see and hear the spark from the high voltage wire.

If you do, replace the condensor and repeat.

If no spark then the condensor is bad.
 
Will test the condenser this afternoon and see what we have working or not.
Thanks for that link 30CC. Alot better to understand than the book I am using at home.

Dave
 
Ok back from testing, sorry for the delay had a small kidney stone working from my right kidney... 3rd one in the past several years..

anyways.

took out the condensor and checked for any power at the points and all was dead.
took the coil wire and attempted to see a spark or anything. nope nothing.

Cut off the power and put in the other coil.

Checked again at the points for juice and with the points closed had 0.00 on the voltmeter. Took the coil wire and hoped for a spark or anything... nope nothing..


So time for a new condensor..

Where does everyone get all their parts? I been ordering stuff from Mike's A fordable.. don't know if they sell quality stuff or not.

Thanks again for any help or suggestions.

Dave
 
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