PDA

View Full Version : No spark after 12 volt conversion



Btroy
10-12-2018, 01:40 PM
Hi guys I'm back on my 53 Willys truck project.
Got the motor back together and have fuel but no spark. I converted to a pertronix but can't figure out why I'm not getting any spark.

With the key on I have 12 volts on the postive side of the coil, but when I start to crank I only see 9-8 volts on the same terminal.

Ideas are welcome....help please

Btroy
10-12-2018, 02:42 PM
Hi guys I'm back on my 53 Willys truck project.
Got the motor back together and have fuel but no spark. I converted to a pertronix but can't figure out why I'm not getting any spark.

New flame-thrower coil added as well.

With the key on I have 12 volts on the postive side of the coil, but when I start to crank I only see 9 volts on the same terminal.

Ideas are welcome....help please

Cap was removed and rotor is turning CCW as expected.

Also measured voltage on negitive side of coil while cranking and it is thwe same as the postive side 9-8 volts.

LarrBeard
10-12-2018, 05:51 PM
Cap was removed and rotor is turning CCW as expected.

Also measured voltage on negitive side of coil while cranking and it is thwe same as the postive side 9-8 volts.

The negative side should be at ground potential with the points closed. Is that voltage wiggling as you crank?

LarrBeard
10-12-2018, 06:05 PM
Cap was removed and rotor is turning CCW as expected.

Also measured voltage on negitive side of coil while cranking and it is thwe same as the postive side 9-8 volts.

What system have you installed? It appears that most of these systems use Hall effect magnetic sensors to replace conventional points, but the circuitry still makes and breaks the coil primary circuit. Check the spacing of the magnet from the sensor coil.

Do you get a spark with a clip lead from battery to the + terminal of the coil (just ground the - terminal) but be careful, 30 kV will knock you on your fanny.

If you are using a digital voltmeter to read the negative side of the coil, the meter may not respond quickly enough for you to see the make/break action. See if you can find an old analog meter.

It's hard to do electrical troubleshooting via email, but we'll poke at it.

Btroy
10-19-2018, 11:49 AM
I went ahead and bought a new electronic distributor from our host. I am still not getting any spark.
I have a flame thrower coil. The instructions say it has to be an internal resistor type or I will need a resistor.

To answer the question. No I do not get any spark when going from the battery + to the coil.

Truck was converted to 12v with a new wiring harness as well.

LarrBeard
10-19-2018, 02:26 PM
No I do not get any spark when going from the battery + to the coil.

Let’s try to take just one step at a time.

If you have a multimeter, check the coil for an open winding. Measure from the + post to the - post on the coil. That is the Primary winding of the coil, the winding that gets a pulse of current from the distributor if everything goes well. The Primary should measure a fairly low resistance, I think I saw some Flamethrower resistances about 3 or 4 ohms.

The Secondary will measure a lot more resistance – I would guess maybe even 6 or 8 thousand ohms. Measure that from the center contact of the tower to the – post of the coil. This verifies that we have a good coil. (As a check, an old 6-volt Delco-Remy coil measures 1.5 ohms primary, 8,800 ohms secondary)

Here is a YouTube video showing just how to do this:

https://www.youtube.com/watch?v=dtMnD8YJo2Y

(and he's right - he should get clip leads)

Now, let’s try to get a spark out of the coil. Take a look at the sketch at the bottom of the note here.

Make sure that the negative (-) side of the coil, the negative terminal of the battery and the engine block and frame are all tied together electrically. For this test, I would suggest some good jumper wires or clip leads. Don’t trust the case of the coil to give you a ground. Paint is an insulator. Don’t worry about resistor or no resistor just yet – we’re just trying to get a lightning bolt out of the tower of the coil.

It would help to have a helper, this is really a four hand task.

Hold the high voltage (HV) lead from the tower on the coil close to the engine block - about a 1/16 or 1/10-inch. Have your helper tap the clip lead to the + terminal of the coil and remove it. As the helper taps, you should be getting a spark from the HV lead to the block or frame. TAP-ZAP; TAP-ZAP.

If we get a spark now, we have verified that the coil is good.

Let us know what you find and we will go to the next step from there.

Btroy
10-19-2018, 06:20 PM
Ok looks like the new coil is bad, as from + to - it measures 03.4. From center to - my meter does not move.

I will get another coil.

Thanks for your assistance. Will reply once I get another coil.

Btroy
10-25-2018, 02:57 PM
Ok new coil and I get spark with it as in drawing.
But when I connect up the wires
It cranks but no fire from the coil tower now?

LarrBeard
10-25-2018, 03:14 PM
OK - some progress.

Just so I can get a good idea of just where we are, what is the Pertronix part number for your ignition module?

Btroy
10-25-2018, 03:52 PM
That has changed, I went ahead and bought a distributor from our host with the electronics
In it.

It appears I maybe burning up
The coils. Now when I test the secondary
It is showing 9.9 on one and 10.6 on another coil I tried.I have yet another older coil that is showing 8.6 on the secondary side.
All 3 coils still produce spark at the secondary side

Btroy
11-02-2018, 06:20 PM
Can someone tell me the minimum wires I need to start the engine?

Wondering if the plug wires are correct as I whitched to 12 volt system.

Currently I only have the negative side of the coil connected to the dist, starter, and black with 1 white traces connected. Positive side has dist, green with 2 black tracers.

gmwillys
11-05-2018, 08:25 AM
You need a wire going from the run position of the key switch to the positive of the coil. I'm trying to find the correct color of the wire. Included are some on line diagrams that should help.

http://floraoflangkawi.org/willys-jeep-wiring-diagram/2a-wiring1-for-willys-jeep-wiring-diagram/

Btroy
11-09-2018, 11:47 AM
You need a wire going from the run position of the key switch to the positive of the coil. I'm trying to find the correct color of the wire. Included are some on line diagrams that should help.

http://floraoflangkawi.org/willys-jeep-wiring-diagram/2a-wiring1-for-willys-jeep-wiring-diagram/

Thanks for the diagrams, I am pretty sure its wired correctly as I followed the new wiring diagram I got with the hasness, I will verify once again.

Thanks for your time really appreciate this.

Btroy
01-02-2019, 07:41 PM
Thanks for the diagrams, I am pretty sure its wired correctly as I followed the new wiring diagram I got with the hasness, I will verify once again.

Thanks for your time really appreciate this.

Update as I hate to leave threads unanswered.

Success finally..:)

I was able to get my 53 running after a complete refresh and conversion.

I followed the wiring diagram but not sure if I misread it or it was wrong to start with. Anyway my issue was I had wired the black to the - side of the coil along with the S lead on the starter. So when I would crank the jeep I am guessing the coil would engergize and cause a short in the system.

To resolve this I took the black wire from the start of the ing. switch and ran it directly to the S on the starter. When cranked the engine fired off in 2 seconds.

Now the jeep has been converted to 12 volts, has new dist, coil, along with everything else under the hood.

Wanted to just say thanks to all who assisted in this project.

Happy New Year guys!!

gmwillys
01-02-2019, 08:48 PM
Thank you for the update, and happy new year to you! Glad things are working out now. Keep us advised of your progress.

LarrBeard
01-03-2019, 07:09 AM
Now - make yourself a good, clean drawing of how things are wired and put copies in all of the places you will look in a couple of years when you ask yourself "Now, how did I wire that truck?"

Good Luck!

Post us a picture of the truck ...

Btroy
01-03-2019, 11:40 AM
Now - make yourself a good, clean drawing of how things are wired and put copies in all of the places you will look in a couple of years when you ask yourself "Now, how did I wire that truck?"

Good Luck!

Post us a picture of the truck ...

Now thats funny ....I did that already as I put that last diagram up somewhere and now I can't find it. I hear Ya! :)

3594
3595

Thanks again.

gmwillys
01-03-2019, 10:03 PM
Project binders. Keep everything of record within the binder.