Pertronix install gone bad!

[RustyandGreen]

Hello,
New to the site but looks like really good information here! So I have a 68 C/10, I6 with a 3 speed. I installed the pertronix ignitor 1162A, followed the instructions except for the part about the ballast resistor, I couldn't find a resistor in the wire, I'm starting to think now the wire is the resistor? Anyway I got everything hooked up and when I tried turning it over I melted the insulation off the ends of the yellow wire from the starter solenoid to the coil. I'm still trying to figure out what went wrong, seems something must have been shorted out but I'm not seeing it yet. Could the coil have been fried? It looks like a very old Delco-Remy unit but it was still running when the points were in. I had put an ohmeter on it before I began the install but was getting strange readings, first it said 5 ohms, later tests showed about 1.8, and then it went to 0 and then -0.1. I was figuring I'd change the coil but it could be the cheap ohmeter going haywire. Also I've had trouble with starting, sometimes it sounds like the battery was dead but after turning the key a few times the starter would slowly come to life, very slow at first and then would work as normal. I mention that just to say it might be connected, battery was fully charged. My first old Chevy that I've tinkered with, I mostly have Fords but I like them all really. Sorry for the long post, I really appreciate any advice.

[67ChevyRedneck]

Pertronix are big in the Ford word, not so much on the GM side as you can simply upgrade your ignition to a GM HEI system with the only requirement being a new 12V wire that works with IGN on and Run. That will get rid of the points and separate coil (inside HEI cap).

I hate petronix. I went through 3 on my 65 Mustang. I ended up putting a GM HEI on my 289. Car has never run better

It sounds like you crossed wires somewhere. Every if you ran 12V to the pertronix, it should fry the pertronix unit (but not right away, should take a little bit of time), and not melt wires? Are you sure you got all the + and - to the coil, etc correct?

[RustyandGreen]

There aren't a lot of wires to mess up, black to negative and red to positive so I don't think they were crossed. One other thing I noticed was the distributor cap rotor rode a little high on the magnet but fit after I shaved off a little plastic on the bottom of it. I have pertronix on my 67 mustang and 66 F100 with no problems for many years now, never had a GM to try them out on before this.

[Ken B]

I put a Pertronix distributor in my 70 Longhorn because I wanted the original look and I was done playing with points. I dropped it in and all I had to do was look at the key and she was running. That was a yr. ago, I'm not gonna say much else cause I don't want no bad ju-ju ...

[Oldironside]

Hello there and greetings from Germany,
I'm the owner of a 1970 C10, 350 cui, imported from California. The PO had installed a HEI ignition many years ago. When inspecting the truck, I found, that the insulation of the yellow cable you mentioned in your post was melted completely (to the bare metal) the whole length of the wire. The reason is: the original cable can't handle the HEI current - too much resistance. You have to swap the ignition wiring to a HEI wiring harness or run a wire with lesser resistance from your fuse box to the ignition coil.
Hope that information could help!

[Jason Banks]

Yes. The yellow wire is a resistor. You shouldn't power the pertronix from the yellow wire. I would power it from another source. I found the instructions and it looks like the yellow still needs to go to the coil so...maybe you can't change it entirely out. Or if they provided a new resistor...you can change it back to the firewall and then split it...to the resistor and on to the coil and the other split to the pertronix module.

I found their instructions and they could be a little less generic.

There is something strange about the way the yellow wire works. You can't directly measure the resistance...somehow it increases as the current increases....


I went for an HEI conversion on my 250. Here is a good thread showing the wires.
http://67-72chevytrucks.com/vboard/s...d.php?t=148346

[Jason Banks]

I would go all the way back to the firewall connector shown here:

http://67-72chevytrucks.com/vboard/s...3&postcount=17

Leave the yellow wire going to the coil. Then connect a new wire to the same terminal to run power to the pertronix.

http://67-72chevytrucks.com/vboard/s...3&postcount=18
http://67-72chevytrucks.com/vboard/s...3&postcount=19
http://67-72chevytrucks.com/vboard/s...3&postcount=20

[RustyandGreen]

Thank you all for your help and suggestions, I think I am going to try something a little different assuming I understand this correctly. If I replace the coil with a Pertronix Flame Thrower or any coil that can handle 12 volts and disconnect or remove the resistance wire and the melted starter/solenoid wire to the coil couldn't I run new wire from the ignition at the firewall all the way to the new coil, bypassing the starter? That sounds pretty simple, if I'm understanding how this system works anyway. Really appreciate all the replies.

[toolboxchev]

OK, here is part of the answer. Yes one of the wires on a stock distributor is resistor wire. It will be Yellow or White depending on age and degradation. You can also id it by the cloth like covering on it instead of a plastic/rubber insulator.

Most of the aftermarket ignition systems do want you to run matched sets on them...I.E,. Pertronix coil and ignition module, the Same goes for Accel Products.

Although I have an GM HEI distributor, Pertronix Ignition Module and and Accel Super Coil. I do not have a matched set in the ignition by any means.

The repair shop whom has been dealing with rebuilding HEI's for decades informed me to limit the feed to distributor to a 7 amp fuse in case of an overload condition to protect the module.

I did have to replace a couple of modules over the course of 5 years, one being a Pertronix unit, yet have had no issues for the last year.

I hope this helps, you will find in the fact section, or do a search on this site to wire in an HEI to key on properly. There is a whole bunch of people willing to get you running.

[Mike_Mc]

You said you had the original delco coil? When I installed mine I changed the coil as well to the flame thrower which is what I've heard is recommended. Good luck

[panhead59]

Yeah, hang in there and get it wired correctly and it will work fine. I have one in my 66 gto and it works great. It Eliminates points and hopefully you got the one with a rev limiter.

[custom10nut]

I put the Mallory equivalent in my stock distributor about 18 years ago, and have been very pleased with it. I put a 80,000 volt coil on at the same time.
I have a V8, but I'm guessing there is a I-6 model as well.
All the other advice is correct. Make sure you follow the directions while installing, and you shouldn't have any problems.

[davepl]

I've had Pertronix ignitors (IIIs, I think) in one car for 12 years and my truck for 4-5 years, and they have been reliable.

They 3 (at least) requires a full 12V, non-resistance. There are some pretty specific requirements for the coil, though, in terms of ohms, etc:

"To determine if your systems coil is compatible with the Ignitor, some measurements should be taken prior to installation of the Ignitor. Caution… While performing this test, never leave the ignition switch on for more than 30 seconds at a time.

Set your voltmeter to a 15 or 20-volt scale. Attach an 18 or 20 AWG jumper wire from the negative coil terminal to an engine ground. Attach positive (red) lead of your voltmeter to the positive side of the coil, and the negative (black) lead to an engine ground. Turn the ignition switch to the run position. Now read the voltage at the positive coil terminal. Turn the ignition switch off. If the voltage measured is approximately 12 volts, no resistance wire is present. A typical resistance wire will provide 9 - 6 volts.

The next step is to determine the resistance in the primary ignition. Label the wires attached to the coil terminals and note their appropriate location. Make sure that the ignition switch is off and disconnect all wires from the coil. Adjust your meter to the lowest ohm scale. If you are using an analog style meter make sure to zero the needle.

Measure from the negative terminal to the positive terminal. Write your measurement down.

Now the maximum system amperage can be determined, divide your voltage measurement by your coil resistance measurement. This will give you the system current or amperage.

Four and six cylinder engines should not exceed 4 amps. Eight cylinder engines should not exceed 8 amps. If the total amperage in your system is higher than the amount recommended for your application, you should install a ballast resistor."

[69-72]

Be sure to use the correct coil for the Pertronix you are using. I II and III each require the correct ohm coil to be used.

[RustyandGreen]

Thanks for the comments! Today I taped up the wire that melted the insulation off, I ran a new ignition wire from the fuse box marked "unfused ign" to the pertronix unit, the red wire. I started it a few times, it fired right up and idled well. I didn't drive it yet, but I was interested to see if the wiring would get hot while the engine was turning over, seems it didn't, no burning but slightly warm, but it was also 106 degrees as well here today. I plan to replace the main engine harness just to be safe, looks like it's close to $100 for the wiring from the firewall. The original coil seems to work fine, the instructions from pertronix only state that the ignitor needs a points style coil, but not that theirs is required. It would be a good idea to replace the coil anyway, when I do a full tuneup and check the timing I'll get a new coil for it along with all the usual stuff. Anyway it runs again!