450 IH burning up electronic ignition modules

Hey all,

We have a friend that has a 450 IH LP tractor that he uses daily to feed cows with, and he had converted it some time ago to electronic ignition, and so far in the last couple months has burnt up a few electronic modules.

He has me searching for all the stuff to put it back to points, so he is pretty frustrated.

Is there anything that could be causing this, or has the quality slipped up on the modules? Pretty sure it was a pertronix kit.

Any info appreciated,
Thanks!

If he is using true wire plug wires many of those say not to use them and they will cause that. For some reason the electronic one need the carbon type plug wires

As far as I am concerned, there is way too much conflicting information of what coil, plug wires, resistors etc that should be used with these electronic conversions. I know the engineer who designed that unit is way more intelligent than me but the suppliers that are selling it are not all on the same page. Just my two cents.

An old four cylinder, low speed engine like used in farm tractors operate just fine on original equipment. It needs to be in good condition though and that seems to be the rub. You can install the electronic module and get away with more wear in distributor from what one guy who pushes them tells me. I am not convinced of that.

As far as burning them up, I would say improper match of coil and resistor to voltage input to the module. Resistance spark plug wires should not affect module life, but may affect engine performance. Not arguing, just my guess.

Is the 450 a positive or negative ground?

If the electronic unit is a Pentrox, it should be negative ground.

Not to long ago I pull an electronic ignition off a 8N ford due to it having stopped working. I got to looking at the paper work that came with it and in the info it said FLAT out DO NOT use wire plug wires or it will void the warranty

Does the tractor have a mechanical regulator on the generator/ alternator ? You should really have a smooth, electrical spike free, solid state regulator to protect the electronic ignition module.
I remember back in the early 70's where Chrysler was the first to make electronic ignition standard on all 71 models, and sold the electronic ignition as a retrofit kit for older models with point ignition. When adding their electronic ignition kit, they strongly recommended changing the alternator from a mechanical regulator to the newer solid state regulator to prevent voltage spikes from damaging the ignition module.

I have had no failures of the 6+ Pertronix ignition systems I have installed, but I make sure I get the new matched coil from pertronix to go along with the ignition kit.

If it is standard Pertonix module,and it is used with a four cylinder engine, the ignition coil must have at least 3 ohms on the primaries or the module burns out pretty quick. Pertronix makes that very clear. If the stock coil is still on it and it is a 1.5 to 2 ohm coil, that is your problem.

I think that applies only to Pertronix II and Pertonix III modules. The standard Pertronix can be used with solid copper plug wires, and that is the module I usually see used on farm tractors. I have four engines with the Pertronix and all have copper plug wires.

Exactly like I said, a lot of conflicting information. As far as the coil ohms, that would be pretty much standard information but some 450's are 6 volt and some are 12 volt from factory and all are positive ground from factory. Now add a alternator conversion with negative ground and a you throw another fly in the ointment. A manufacturer needs to cover all these bases for a trouble free installation and from what I have seen, they do not.

I have a customer that install pertronix kit in a G 1000 Minnie, ran only a few minutes, tried another kit, same thing, i installed two that quit, finally made some phone calls to pertronix, replaced plug wires with what they recommend and it's been running fine for 3 years

Be sure the module is connected correctly. My 300 I put the Petronix and a Ford 900 were wired with the module on the ground side of the magnetic trigger.If it is hooked up with voltage going to the module first, it will kill the module very quickly. Also they told me NEVER to leave the ignition switch on and not have the engine running. He said this will kill a module almost immediately. just two things to check on. These units make both tractors start almost as soon as the starter begins cranking. And no more cleaning points after the tractor sits in the shed for a month or two. I would not give up the Petronix for anything.

I haven't found any "conflicting" info from Pertronix. In their install instructions: #1 they give a voltage range. #2 they give minimum ohms required across the coil primaries. #3 It is clearly stated that copper wires are fine for the standard Pertronix kit, but not for the Pertonix II or Pertonix III. Looks like ample info to me.

One (among others) possible causes of premature elec switch failure IS MORE LV PRIMARY CURRENT THEN THE SWITCH IS RATED TO HANDLE. If the elec switch is rated to say perhaps around 4 amps of current, that means the total LV Primary resistance (coil + any ballast) should be at least near 3 ohms as I = E/R = 12/3 = 4 amps. Many typical "12 volt" coils have near 3 ohms LV Primary resistance and, therefore, their use shouldn't exceed the capacity of a 4 amp rated electronic switch.

YOU NEED TO INSURE THE TOTAL RESISTANCE OF YOUR COIL + ANY EXTERNAL BALLAST IS AT LEAST 3 OHMS IF THE SWITCH IS 4 AMP RATED

Are you sure if the coil is a 6 or 12 volt??? if its a 6 volt coil and there's no added series ballast you may be exceeding the switches current rating causing it to fail. Many (not all) typical old farm tractor 12 volt coils have around 2.5 to 3.5 ohms LV Primary resistance. Many (not all) typical old farm tractor 6 volt coils have around 1.25 to 2+ ohms LV Primary resistance.

A coil labeled "12 Volts" or "12 Volts NOT for use with Ballast" is a true 12 volt coil and no ballast is required if the current switching device can handle 4 + amps. HOWEVER a coil labeled "12 Volts for use with or requires Ballast" is more like a 6 volt coil and if used un ballasted it could burn up a 4 amp rated switch !!!!!!!!!!!!!!

YOU NEED TO INSURE YOUR COIL + ANY (if used) BALLAST TOTAL RESISTANCE IS SUFFICIENT SO YOU DONT EXCEDD THE SWITCHES CURRENT RATING Are you using a full true 12 volt coil or if a 6 volt coil is there added ballast???

NOTE some high energy or high voltage after market coils can draw more current then a conventional stock coil so the elec switch has to be capable of passing their current. Some may require added external ballast even if labeled as a 12 volt coil.

YOU HAVE TO CHECK WITH PERTRONIX (or whatever vendor) to insure the coil and switch is properly matched and NOT what any of us here me included have to say !!!!!!!!!!!!!!

NOTE many elec switches are fine using standard copper core plug wires HOWEVER in some high energy high voltage applications using certain coils resistive or spiral wound plug wires are required CHECK WITH PERTRONOX not us lol

Other failures may be due to poor or resistive wiring connections or poor grounds

John T Too long retired electrical engineer and rusty on this stuff so no warranty CHECK WITH THE VENDOR

Good info Pete, indeed if some were 6 volt and others were 12 volt?? and if its POS or NEG ground?? IS SURE RELEVANT AND CRITICAL INFORMATION. That being said, if it was 6 volt and used a 6 volt coil which was retained UNBALLASTED and converted over to 12 volts that could damage an elec switch if its only like 4/5 amp rated !!!!!!!!!! If its a 6 volt coil ?? he needs to add an external series voltage dropping current reducing ballast resistor !!!

Nice chatting with you

John T

If you go into Pertronix web site they highly recommend using their coil and not using solid copper wires.

I did the same thing on a H w/auto type wires and the pertonix stiil died and that was the second one that died. They replaced both,but the tractor is running good with Pertonix coil and original points/cond. Elec.kit is now on shelf in parts ben,afraid to install it on a customers tractor. Have installed these kits begore and useing original plug wires with no problems,go fiqure.