Spark Plug wire resistance

[njs]

Original plug wires on my '71 F250, low miles; 7 of the 8 wires measure 9K to 15K ohms. This seems to be a normal/correct value. However, there is the one that measures 80K ohms. Is it bad? I know I will not be able to get one molded wire to replace it if it should be replaced. Your thoughts please on this "high" resistance wire.
Regards,
Jeff

[knightfire83]

Being about 8x more resistive than the others, it would definitely be suspect.

Generally this is what to look for when checking wires:

Early performance Solid core = 0 ohms
OEM Silicone w/graphite core= 3,000 to 12,000 ohms per foot
Late performance Spiral wound = 500 ohms/foot


You could probably make a trip out to a local junk yard and pick up another wire off almost any older vehicle for $1. Just make sure that it isn't also bad and has the right connectors / length.

But the right thing to do would be to replace them all with new ones.

[Dragon]

Original plug wires on my '71 F250, low miles; 7 of the 8 wires measure 9K to 15K ohms. This seems to be a normal/correct value. However, there is the one that measures 80K ohms.

How do you know they are the original wires? At Ford we used the value of 3000 to 5000 per foot. I have switched to Blue Max from Napa real flexible nice wires that are truly cut to fit.

https://napaonline.com/Search/Detail.as ... 28+2028028