Spark Plug Wire Resistance reading

Schnidly

Petty Officer 2nd Class
Joined
Aug 12, 2001
Messages
143
Dear Forum,

OK, I finally got one plug wire out of the coil side. My question now is, what kind of resistance should I read through the plug wire. It is about 7-8 inches in length. I had to reinstall the piece that plugs into the coil side, the brass metal clamp. I stick my ohm meter leads into the boot end and the other end of the meter into the end of the plug wire directly bypassing the metal clamp I had to reclamp onto the plug wire. I am reading 0 ohms when doing this on a ohm scale of 200K and the 2000K and the 20K ohm scale. Not sure what I should get, but I assume there should be some resistance through this wire? My motor's serial number is: 0B302485, it is a 1988 Mercury 90hp 3 cylinder 2 cycle outboard motor. PLEASE HELP.

Schnidly
 

wired247

Lieutenant Commander
Joined
Oct 8, 2011
Messages
1,557
Re: Spark Plug Wire Resistance reading

Its a metal core wire. You shouldnt have much if any measurable resistance.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,605
Re: Spark Plug Wire Resistance reading

Dear Forum,

OK, I finally got one plug wire out of the coil side. My question now is, what kind of resistance should I read through the plug wire. It is about 7-8 inches in length. I had to reinstall the piece that plugs into the coil side, the brass metal clamp. I stick my ohm meter leads into the boot end and the other end of the meter into the end of the plug wire directly bypassing the metal clamp I had to reclamp onto the plug wire. I am reading 0 ohms when doing this on a ohm scale of 200K and the 2000K and the 20K ohm scale. Not sure what I should get, but I assume there should be some resistance through this wire? My motor's serial number is: 0B302485, it is a 1988 Mercury 90hp 3 cylinder 2 cycle outboard motor. PLEASE HELP.

Schnidly

You should be reading zero or very close to that. They only used resistive core wires on vehicles to reduce radio interference and therefore those type spark plug wire will read some resistance. So if you are reading zero ohms, that is a good thing...
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,689
Re: Spark Plug Wire Resistance reading

I don't know personally, but zero"ish" for stranded wire and 5k ohms"ish" for resistance wire, obviously length dependent. Not hard to differentiate between the two. Either you will be at one extreme or the other. If you have stranded wire and cut into it you will have stranded metallic wire. If resistance, it will be something like a nylon stranded center conductor in a graphite/carbon medium.

Mark
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,938
Re: Spark Plug Wire Resistance reading

Merc uses stainless steel stranded spark plug wires. Resistance is futile (and zero!
 

Schnidly

Petty Officer 2nd Class
Joined
Aug 12, 2001
Messages
143
Re: Spark Plug Wire Resistance reading

Thanks everyone, wires are 26 years old so I just ordered 3 new wires and plug boots.
 
Top