IH 1971 International Travelall ignition wiring help (1 Viewer)

[Big Ed]

I installed a new wiring harness. It starts from the key and dies as soon as the key is turned from start to run. This means the coil isn’t getting power in the run position. The new harness was made off the original as a sample. It has all new original type plugs, and the end of each wire is marked with the corresponding numbers in the schematic. I never checked continuity before, so I read up on it. My tester doesn’t beep, I have to look at the numbers. No options are marked continuity, but one has that funny looking upside down horseshoe looking thing. I put it on that. The leads won’t reach from ignition to coil, so I used alligator clip jumpers and a length of wire. When I first turned the tester to the ohms setting the display read 0.L, the instructions I found said that’s right. When I first made contact the display changed to zero, then started climbing slowly, stopping at 8.1. The instructions said it needed to be 1.0 or less to be at the opposite ends of the same wire.

Questions: Does this being the special type wire (to reduce power going to the coil) affect the ohms? Will the jumper wires affect the ohms? In other words, am I getting an accurate reading? The harness maker had the wire marked correctly and in the right spot on the ignition plug. If they marked the wires incorrectly, that’d mean it’s elsewhere on the ignition switch. Should I check continuity on the other wires to see if that’s the case?

Another thought, this wire goes through the firewall in a bulkhead plug. I believe I checked all of those wires against the schematic, but I could check again.

Pink circuit is momentary full power while cranking, green is power to coil in the run position.

 

[gnob]

This diagram isn't showing two wires to the coil. The diagram is showing keyed power to the coil, then that keyed is going to the wipers.
Typically a ballast supply has an external resistor not something hidden in the loom

 

[Big Ed]

that keyed is going to the wipers.

I think you followed the lines wrong.

 

[Big Ed]

Typically a ballast supply has an external resistor

Not an International.

 

[gnob]

Your manual is giving you the ohms value for the wire.
It looks like it says 1.8 ohms.
Assuming your fuse it good?
Do you have proper voltage at the ig switch?

 

[Big Ed]

did you just buy the harness because it’s ~50yo & maybe has cracked insulation so it looked hinky?

I bought the harness because the old harness burned up.

 

[Big Ed]

Assuming your fuse it good?

I don’t think it has a fuse. Unless you mean the special resistance wire.

 

[Big Ed]

Do you have proper voltage at the ig switch?

Havent checked, I’ll put it on my things to do list.

 

[gnob]

You're right, i guess thats a bulk head conn.
Cant imagine why the old harness burnt.

I don’t think it has a fuse. Unless you mean the special resistance wire.

Havent checked, I’ll put it on my things to do list.

check continuity from ig sw to that bulkhead conn. Then from there to the coil lead.

 

[Big Ed]

The fire started at the bulkhead connector, I had to disconnect the battery. The new one has all new connectors.

 

[BILT4ME]

I don’t think it has a fuse. Unless you mean the special resistance wire.

Deleted because I'm pretty sure I am just confusing things.

 

[Big Ed]

Does a 71 IH have a special resistance wire?

I don't recall any vehicles until about 1975 that had any fusible link (resistance wire). There were inline fuses and fuse blocks.

Does this have points and condenser in the distributor?

I would lean toward a burnt ignition switch based on how the harness melted. Your switch may still be compromised. Not uncommon in those days.

Yes, a special resistance wire. I don’t know of International using a separate resister, even on my 1964 pickup.

No points and condenser anymore, I installed Pertronix.

Brand new International ignition switch was installed with the new harness.

 

[gnob]

Im wondering if the pertronix will even function with a resisted supply?

Yes, a special resistance wire. I don’t know of International using a separate resister, even on my 1964 pickup.

No points and condenser anymore, I installed Pertronix.

Brand new International ignition switch was installed with the new harness.

 

[Big Ed]

Im wondering if the pertronix will even function with a resisted supply?

Yes it will, but there’s a noticeable difference.

 

[Big Ed]

I put new batteries in the tester and checked again, same ohm reading. I did not check ohms separate at the bulkhead connector.

I also charged the battery, cleaned the terminals, and connected the cables. I had 12.87 volts at the battery, 12.67 at the ignition switch, and 12.67 at the proper terminal with the key in the run position.

I messaged the wiring harness people asking if they used the proper resistance wire.

 

[Big Ed]

I ran a new wire from ignition terminal on the ignition switch to the positive side of the coil, now it won’t start at all. My son rebuilt the carburetor when I was away for twelve days at our mountain place. So I put gas down through the carburetor, still nothing. I thought, well maybe I pulled the wire from the starter off the coil instead of the wire from the ignition switch. So I ran a jumper from positive side of the battery to positive side of the coil, still nothing. By this time I confirmed that gas was being shot down into the intake when I worked the throttle. I haven’t checked for voltage or spark, that’s next. Now I’m thinking maybe the Pertronix got fried when I left the jumper from battery to coil for about a day. But it kicked over since then, then died when key was turned back to run position. Dunno. I’m gonna take the wires back off the positive side of the coil to confirm which wire I removed, I can’t see the numbers with it connected.

 

[Big Ed]

It was the Pertronix.

 

[Big Ed]

I drove it on two errands today, electrical seems fine.