I have some older plug wires that test just fine on the ohm meter, but thought it wouldn't hurt to find out what others consider when determining that they are do for replacement. There is no sign of age on them, and like I said, ohms readings are good. Post your thoughts, thanks!

I'm wondering this myself. The MSDs on my hemi are 10 years old, but they ohm good. The MSDs on my wedge motor are probably 14 years old.

Grab em when it's running then you'll know for sure........... Was told that ohmage is only part of the equation and actually changes and they get older but my Firecore`s are at least 8 years old and still kickin. Start it up in a dark garage and check around the boots and see what that does and I take the boots off of em and apply silicone on the wire then slip the boots on and let cure for 24 hrs which helps............

if they past the ohm test and the insulation is good run'em.

Almost all of the outer layered helical stainless spun spark plugs wires use a inner graphite coated conducter for the spark to travel on I had one set of Moroso older wires that ohmed good but wouldn't run worth a hoot on my motor, it wouldn't hardly idle or stay running once started
The higher the revs and the higher the internal resistance in the cylinders(compression, boost and fuel type) the higher the amperage needed to fire the plug and the higher load on the wires and plugs Wires do wear out, especially the coil wire

I was told by a tech person at Autometer years ago. Replace wires every year. Coil wire every 6 months. I haven't maybe been that religious, but depending on the run time they don't stay on past 2 years

Thanks, all. These wires are probably old enough, even with limited use.

My last set of Taylors were at least 15 years old.Still worked great but looked bad.My kids were at least 6 years when he sold his 300.Rocky

A shop I use to work at we did drive ability and
we tested wires all the time...when you have the
meter on them flex them around and see what the
meter says... on a lot we could see that they would
really change and some would go open... those wires
move around on a engine.. specially on our rigid
mounted engines... keep them away from heat... cheap
wires dont last long but a quality set can last years
but also.. keep them clean

This is the way I look at it also. Wires are a ware item just like plugs and oil. I have a few sets laying around that will work ok on street stuff.

They need to be Hipot tested, its done by a Megger. that is what is used to test the leakage and breakdown of the wire. Tim

i have a friend that had as big block and turbo in his 80 Camaro. he had a miss he couldn't find.
took the wires off ( msd) and they checked out ok, so he didn't replace them. after spending a lot of money chasing his tail, another friend asked him, when he was checking the wires, did he just checked them holding them straight, or did he bend them as he tested them.....
turns out 5 of the wires went open if he checked them while bending them, just like the would be on the car. replaced them, and the miss went away.

but i would also say, that high compression, boost, and nitrous take their toll on wires.
on a NA engine the wires would live longer.