No spark

[GTS61]

I'm working on my pickup, doing body work and painting and the truck has been sitting for about 2 years while I do this. I also installed a Vintage Air ac. Well I put the battery back in because I wanted to move it and it turns over really good but won't start. I think I tried almost everything I've read on hear but what I'm wondering is since I installed the Vintage Air and didn't need any power from the old heater and that maybe I need to hook up the old heater wire harness to something or maybe something else. Any idea's would greatly be appreciated!! I am not a mechanic as you can see. I do have power to the coil. Nothing else was done to the truck motor since I drove it in to the garage except new points.

Greg

[AZKen]

Well since you have new points, you need to check the 1.gap. Who did the points? You need to 2.check spark at a spark plug and you need to see if 3.gas is squirting inside carb. What does it do? Fire? no fire at all and no back fire? These are the basics of "was running now no start". Spark and gas.... There are a dozen things it could be. 4.Does coil have power during cranking? You don't have to be a mechanic, just mechanically/electrically inclined. You must have some basic knowledge if you have tried "almost everything". Let us know what that means specifically.
5.So..Running into the garage, then AC and points? then no start? Troubleshooting 101: S.O.E.= Sequence Of Events. Then test per that. It does seem like electrical/ignition/miswire, as you suspect, but don't want to marry that yet.

[jimjaz]

I had this problem many years ago and found the problem to be the capacitor that works in conjunction with the points, under the cap. I replaced the capacitor and the problem of not being able to start was fixed. I had power to the coil, but not to any of the cylinder wires.
In your case, I would be thinking more along the lines of what Ken has to say. If you did some wire "borrowing" and it has been a couple of years, then your carb may be gunked up or your wiring is amiss with the changes you made to it.

Jim

[GTS61]

Thanks for responding. I have no spark when I put a spark plug on a plug wire and grounded it to metal. And I did just buy a capacitor and it isn't that. I do have a friend mechanic that is coming by but it's going to be 3 weeks so I was just trying things that I read on the archives. I do have 12 volts at the positive side of the coil and I did find a bad connection on the starter that I fixed. I cleaned all the grounds that I know of. I do have gas going to carb but it won't fire. I do appreciate all of your knowledge on this site. Thanks Guys!!

[AZKen]

Thanks for responding. I have no spark when I put a spark plug on a plug wire and grounded it to metal. And I did just buy a capacitor and it isn't that. I do have a friend mechanic that is coming by but it's going to be 3 weeks so I was just trying things that I read on the archives. I do have 12 volts at the positive side of the coil and I did find a bad connection on the starter that I fixed. I cleaned all the grounds that I know of. I do have gas going to carb but it won't fire. I do appreciate all of your knowledge on this site. Thanks Guys!!

Well if you are sure about no spark and you have double checked the spark at several plugs, then you have narrowed it down to "spark". That's good.
So...
1. Check pos on coil when cranking, you didn't say.
2. Did you check points gap, you didn't say.
3. You can't dismiss a bad condenser or points just because they are "new"
Those Chinese parts are known to be bad right out of the box. You may have installed wrong or not adjusted points correctly. My guess is points not adjusted.
4. Coil can be bad.
5. Waiting for mechanic is your option. There are further test for mentioned components. Spark is easy to backtrack.
6. Gas check not relevant now, but "gas going to carb" is a different meaning than squirting observed in throat.

Good luck down the road.

[GTS61]

I haven't check gap yet. Do I need to take points out to measure gap? Yea points and condensers are cheap to buy but I'll check my gap first. I did buy a new coil but I had same problem so I took it back. What should my coil read while cranking? Thanks Ken!!

[AZKen]

Just want to be sure wiring is correct and that you have voltage on the coil pos terminal when the motor is cranking. There may be a glitch that interrupts the voltage when key is turned to start.
Just put a test light on the coil pos and have someone crank motor with the ignition switch and see that the light stays lit. If it does, that's good, if it goes out, that's bad. Report that ASAP.


Point gap: Take off distributor cap. Bump starter or push truck so that the rub block on the points is on a one of the high "lobes" of the distributor shaft. In other words resting on a high ridge. Leave it right there. This will open the points to max open. Use a feeler gauge to see what the gap is now. You want .016-.019. You will barley loosen the screw on the points slot and use the built in screw driver pry tabs to move the points to get the gap...or however you can get the point assembly to move.
The gap will try to move when you re torque that screw. Watch out for that!!! Recheck the gap after screw is tight. You may have to play with that some but it's REAL important.
Also make sure your distributor plug wires are in the proper firing order. Search the internet and read all you can find on setting points and general old time auto ignition systems. Don't think you have a big problem. One step at a time will find it. Post what you find out. We all need to know the results of each step.

You did not answer this: Was it Running into the garage, then you did AC and points? then no start?
You didn't leave the distributor rotor off did you? When you put points/condenser on?

[GTS61]

That's funny I almost did leave the rotor off but saw it sitting there. I drove it into garage turned it off for about 2years. While it was sitting I installed AC then a couple of months later I tried starting it and it turns over but no Fire. So I got new points and then bought a condenser with no firing yet. I'll try the things you said to try and get back with you all. Thanks again

[jbgroby]

GST,

Might I suggest a Pertronix Electronic Ignition, I made the switch over 6 years ago, truck sat for 5 more years before really getting started once per week and never had a moments problems with it. Its the best $75.00 (might cost a bit more now) you can spend on the truck. I tried to search their page for the part number, but I think you need to email them your engine size.

[James]

Here is an old trick I had learn (when I was a teenager and before electronic ignition) for setting the point when you only have a screw driver and stranded somewhere without all of your tools. Set the rubbing block up just like AZKen has stated and use a business card or a book of matches cover for setting your gap. This will get you home to where you can use your point feeler gauge to set it.

[GTS61]

Thank you all for the suggestions! It won't be long and i have it running (I hope). Yes I've been reading a lot lately that people are switching to pertronix so I'm definitely going to look into this. But for now I'm going to do what Ken wrote:-)

[GTS61]

Checking meter. It's 12 but when cranking it goes to .18. I have black meter probe on the pos side of battery and the red to the pos of cool. Is that right? I did set gap on points also.

[James]

Checking meter. It's 12 but when cranking it goes to .18. I have black meter probe on the pos side of battery and the red to the pos of cool. Is that right? I did set gap on points also.

The Red lead goes to the positive side of the coil. The Black lead goes to ground or battery negative. With the starter cranking the engine the voltage should be close to battery voltage (9-11 volts with a good battery, starter will create a large voltage drop during cranking). With just the ignition switch in the run position it should be near battery voltage (12.5-13 volts) with the points open. If the point is close the voltage will drop because the resistor wire (between the coil and the firewall connector), is use to prevent burning up the point while the engine is running. Once the engine is running the voltage will vary somewhat with rpm due to the amount of time (dwell) the coil is passing current with the points closed.

The .18 volts you have is the voltage drop from the battery through the starter solenoid and out the solenoid "I" terminal to the coil.

[GTS61]

Thanks James!! I'm such a knucklehead when it comes to engines.

[AZKen]

Just remember black wire on a meter or a truck battery is negative only. Red wire on meter or truck battery is positive only. Otherwise you will damage truck or meter. At this point, you need a mechanic or friend to help that has experience.

The starting system is set up such that when the starter draws a big load from the battery during starting, as James says, the coil is supplied direct voltage also. But after starting, the coil has a secondary/resistive circuit that provides reduced voltage to save "wear" on the points during driving. You should have two wires going to coil positive. I was just trying to find out if this system was maybe miswired so that little or no voltage was being sent to coil during starting, thus no spark. But when not cranking, and switch was turn to on, it shows 12V at coil.
James has spelled out that very well. This may not be the problem, just needs to be checked out like the points gap and rotor and condenser and firing order does. Because according to you, you have a no spark condition. It's going to be the ignition wiring, the coil, the timing or inside the distributor.

These are checked one at a time. We all would have our work cut out for us if we were doing it and we have experience. You have no experience and it is not possible to do these checks over the internet without some knowledge. You need to read, watch YouTube and take a community college class to get up to speed or it will take many years to get the knowledge and mechanics ain't cheap. Use the internet. I know you are using it here but we can't find the problem without your hands. We can't train on how to use a meter and then train how to troubleshoot. We can't train the entire ignition system, timing, point gaping...etc. Maybe a member lives near you and will help. I do have a lot of patience and want to help. That is what this site is all about but I see a big problem with synergy.

[AZKen]

The reason you need two wires to coil (your possible problem), the need for a "12V to coil" check, before cranking and during cranking, and a visual inspection of the coil positive wiring, is described below:

One wire to coil comes from the starter solenoid "R" terminal and it provides 12V to coil while starting. It is only live when ignition switch is in the start (spring loaded/far right) position. It shuts off when you let go of switch. That is when the second wire takes over. This is the other wire that should be on the coil positive post. It is the resistor/resistance wire. It comes from the ignition switch when the ignition switch is in the "run" position or "on" position. It has a reduced voltage of only about 8-9 V. It's a "special" wire material and a specific length. It is wrapped back and forth on itself inside the harness bundle.

If you are missing the "R" wire from solenoid, then the other wire may not provide enough spark because as the starter needs all 12V. This wire, with only 8V, may loose more and not supply hot enough spark, thru coil, to plugs.
If you are missing the resistor wire, you won't have ANY voltage to coil after you let go of starter. If you were missing this wire, the truck should start and then die after you let go of switch. SOoooooo if you are missing the "R" solenoid wire or one of these two wires is mis wired to the wrong place, OR IGNITION SWITCH IS MIS WIRED, that could be the problem. So study the schematic and trace each wire to see where it goes AND SEE THAT THEY ARE STILL CONNECTED TO WHAT I SAID.
Not yelling, emphasizing.

Also the negative coil wire goes to the distributor, be sure that is wired correctly. That wire goes to the points pinch post, same place the condenser wire goes.

Where does the negative battery cable go? To somewhere on the motor?

Do you have a white ceramic block on the firewall anywhere? Like This? (http://www.oreillyauto.com/site/c/search.oap?keyword=ballast+resistor&year=1950&make=Chevrolet&model=Truck&vi=1487139)

Ignition switch wiring: Terminal marked "BATT" = wire directly from battery.
Terminal marked "Start" or "Sol" = goes to "S" terminal on solenoid.
Terminal marked "IGN" or "ON" = goes to coil pos. Again, some of this wire is the resistor wire.
These wires may go thru connectors or be passed thru junction blocks but do go where I indicated, eventually.
The ignition switch has a "ACC" terminal for accessories. The wire should go to the fuse box.
Some of the terminals I've listed on the ignition switch may have other wires connected to them. Try to determine that they are not interfering with anything we are doing.
Take your time, you have a lot to absorb and think about, but you are smart and none of it is difficult, just new to you. Eventually we will trace down the miswire, broken wire, bad component, adjustment error, missing wire, missing part.
I still don't know if you disconnected a wire during A/C install, or didn't install points correctly, did some other "work" you forgot you did or you didn't do anything wrong.


Don't take this the wrong way but I don't know what you know: You do know that when you check the spark plug it is out of the hole with the wire still attached and the MOTOR IS CRANKING OVER and you look for spark snapping/arcing across the gap at the threaded end, every revolution, Right? It has to be touching the unpainted, not greasy part of the motor. With all the coil and distributor wires hooked up.

"I did find a bad connection on the starter that I fixed." EXPLAIN this in detail!!!!! Answer ALL questions. underlined to enable us to think it thru. Not as interrogation or blaming.

[GTS61]

The bad connection on the starter was the positive side of the coil going to the starter. The wire connector broke off from the wire at the starter. METER READINGS: I got a 12 on the meter with the black on the battery ground and the red on positive side of coil with the starter cranking the engine. With the ignition switch in the on position the meter reads 12 and drops to 5.6 when the points close. I do have 2 wires coming off of the positive side of coil, one goes to the starter (that I repaired) and one goes thru firewall that I'm having a hard time getting to because of my new ac evaporator but I'll find it tomorrow also I'll have to look at my ignition switch next. I do not have a white ceramic resistor on my firewall outside or inside of cab.

[James]

The bad connection on the starter was the positive side of the coil going to I do not have a white ceramic resistor on my firewall outside or inside of cab.

It may be a resistor wire from the coil to the firewall connector.

[AZKen]

Hook a wire (jumper) from battery positive post to coil positive terminal and see if it starts or fires using starter switch. Don't disconnect or change anything. Be prepared to disconnect the jumper in order to stop motor. Do that before checking switch. Do that next thing and report.

Make sure you have put everything back together before you do this test. If it does not fire, do the same test again looking at one spark plug gap. Don't have the plug near it's hole and do it in darkness. Again be prepared to pull off the jumper. See if you have spark.

I see James has commented while I was typing. That second wire, as he says, is probably the wire that goes to the Ignition switch. If you know how, you can disconnect it at coil, take ignition switch out of dash and let it hang, find the "on" or "run" terminal, take wire off that terminal. You do not want to take a chance that this wire has voltage. Both ends loose, do a continuity check (ohms). After setting meter to ohms, touch one lead to the detached coil wire and the other lead to the detached run wire and see if there is a reading. Most digital meters read zero when there IS continuity and read 1 or OL when there is no continuity. Does not matter what color meter lead is on what end of wire. Some meters will buzz/beep if there is a connection, so set to buzz if you have it. Do this after the above start test is done.

[GTS61]

I did hook a wire from the positive coil to positive battery and nothing happened. After that I ran a wire from the second wire that was on the positive side of coil that goes inside of cab thru the engine connector, then took out ignition switch and hooked the meter (on ohms) to the wire that was connected to the IGN. The meter read 0.18. Shouldn't it read 0?

[AZKen]

Get new points and condenser and gap it correctly.

[GTS61]

I got it from here. Thanks for all the help!!

[James]

I did hook a wire from the positive coil to positive battery and nothing happened. After that I ran a wire from the second wire that was on the positive side of coil that goes inside of cab thru the engine connector, then took out ignition switch and hooked the meter (on ohms) to the wire that was connected to the IGN. The meter read 0.18. Shouldn't it read 0?

If I understand you correctly, you measure the resistance of the wire from the coil positive side to the wire that goes to the ignition switch. It will not read 0. The wire from the coil positive to the engine connector is a resistor wire (ballast resistor). The wire from the engine connector to the ignition switch should be a plain wire. The reading you have seem to be low. In my 1964 GMC manual the V6 should be 1.5 Ohm.

[GTS61]

Thanks James!!

[GTS61]

Thanks Ken!!

[GTS61]

Your exactly right James. I was reading the ohms thru the resistor wire and plain wire. I ran a wire from outside the cab from the resistor wire to the inside of cab to the wire that was hooked onto the IGN iginition switch. This is where I thought the problem might be. I think I will purchase a new condenser and points like Ken said and go from there. I love this site and all the help I have gotten on this site. It's just so wierd that when I drove the truck into the garage it ran great but something happened that I did to cause this. Thank all of you so much!!