Did I damage my Pertronix III Coil?

[Rentalman]

Hello IH Community. I think my Pertonix III coil is bad? Since the rebuild I have driven it 250 miles. I'm trying to figure out if I damaged the coil. The last time I took the Scout out for a drive was 2-weeks ago to follow up on the repair of my temp guage. It drove great and the temp guage now works. Since then I added a USB dual port-12 volt charger. I grabbed the 12v power off the accessory location on the ignition switch and added a 5 amp inline fuse. For the ground wire I grounded it to the bolt on the fire wall that the heater duct attaches to. The 12v USB charger would only get power in the ignition switch run position and not the accesory position. Ever since I got the scout running I have needed to adjust ignition switch on the steering column. It would start and run but the rod adjustment was off a little. To shut the engine off I would have to actuate the steering lock lever. I loosened the two screws that hold the ignition switch to the column and moved it about 3/16" of adjustment. Prior I rewired the scout with a Quick Wire Kit. So I had the option to turn the power off to the coil when I would turn the key to the start position and test all the detent spots on the ignition switch; start, run, off, lock & accessory. I cant rember if I killed the power immediately before testing the ignition switch or sometime after. It is possible I may have had some cranking time on it before I killed the coil power?

So prior to me adding the 12v USB port and adjusting the igniton switch the Scout would start and run. Or is this failure a coincidence?

I called tech support at Pertronix for advise. From the coil OHM readings I gave him he belives the coil is shot. 1.117 OHM for primary resistance and 7.90 for secondary resistance. Those values may be off because my multimeter I belive was not woring correctly. He told me those coils rarley fail. The three deaths are over cranking the engine to start, wrong coil for electronic ignition and a postive voltage leak in the frame of the vehicle. He said for me to check for 0 OHM's at the distributor plate near the Pertonix Igniter III.

I bought a new multimeter today. Below are my test results.
Primary Resistance measured at 200 OHM = 0.5
Secondary Resistance measured at 20k OHM = 6.80
I have 12 volts at coil with key in run position
1 have 12.77 volts at battery, not running
I checked OHM's at distributor backing plate = 0.3 OHM
I checked all grounds and various other metal points = 0.2 OHM
I checked various grounds and bare metal with negative lead from MM and positvie lead at battery positve = all resulted with 12.77 volts
I checked spark at spark plug # 2 with a Lisle Spark Tester = yellow orange spark

My findings are the sprake was week. I was unable to test from coil because the spark tester would not fit into the coil.

Any advise will be much appreciated. Have a Great Week!

 

[int77345]

if you have the .32 OHM coil and got a reading of 1.117 OHM i would agree the coil is bad. but you also got a reading of .5 which is very close to .32. if it was me i would test again.
also i would test the spark again to. make sure the spark plug is grounded good. even hold it with a jumper cable (plug in jaws) and other side of cable attached to a good ground.

also your scout does not start ? or its difficult to start ?

 

[Rentalman]

if you have the .32 OHM coil and got a reading of 1.117 OHM i would agree the coil is bad. but you also got a reading of .5 which is very close to .32. if it was me i would test again.
also i would test the spark again to. make sure the spark plug is grounded good. even hold it with a jumper cable (plug in jaws) and other side of cable attached to a good ground.

also your scout does not start ? or its difficult to start ?

 

[Rentalman]

Thank you for the reply. I did for get to mention in my post that I can not start the engine. Usually it starts real easy. Pull the choke out, pump the gas partially once, turn the key and it lights up and push the choke back in half way to keep it running. On the OHM readings the first reading were done off a faulty multimeter. I picked up a new meter today and got the readings of .5 on the primary and 6.80 on the secondary.

In the begining after the initial multiple times of trying to start the engine 2-days ago I thought maybe I flooded the engine. I pulled the plugs, wiped the fuel off the ones that were wet, checked gap for .35 and attempted to start 2 hours later giving the fuel time to evaporate. Still would not fire. I gave up and tried the following day. It still will not fire. My belief is it is not getting enough spark. When I checked for spark off of a spark plug tester the color of the spark was yellow/orange. From what I have read is the spark needs to be blue/white. Tomorrow I will call Pertonix and talk with the tech again and give him the new values for the OHM readings on the coil and the grounds that I gathered today and see what he has to say.

The engine is getting plenty of fuel, it has 12 volts at the coil, and the starter is cranking strong. The only thing that is missing is spark.

 

[Scoutboy74]

Quite a lot going on that may or may not be contributing to the issue. You might try a temporary jump directly from the battery to the coil POS terminal only while starter cranking to see if that makes any difference. I know you have switched voltage to the coil, but perhaps you're not getting proper voltage while the starter is cranking for some reason and this test could help rule that out. Just remember to remove the wire promptly after the test is complete.

 

[Rentalman]

Hi Scoutboy 74, thanks for the reply. I retook the primary and secondary OHM readings again today and rechecked my frame and grounding point OHM's. Primary 0.4 OHM's, secondary 6.75k OHM's and the frame was 0.2-0.3. I called Pertonixs today and spoke with tech support. I gave Chris the new OHM resistance values of the coil and frame grounds. The measurements are actually .2 to .3 OHMs lower because he pointed out that I forgot to subtract the amount from what the multimeter was reading with probes touching one another (0.2-0.3). So with that being said the primary is sitting arround 0.2 OHM's which it should be at 0.32 OHM's and my frame grounding points and other metal areas are reading zero. So I have no positive discharge entering the frame anywhere to damage the coil. He said the secondary OHM's should be closer to 9k. He had me crank the engine and check voltage at the coil to make sure it was getting 10v or better which it is. He said the USB that I wired into the accesory location on the ignition switch draws minimum amps and should not be the cause of this. I did check voltage at the coil with ignition in run position with USB hooked up and disconected. Voltage for both was 12V. He suggeted to get a new coil. As soon as I post this response I'm going to the IHPA store to order a new one. Have a great week!