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plug wires

Posted: Mon Jun 11, 2012 3:43 pm
by circleburner12
bought a set of nos wires, for my m38a1. i fought with it for 2 weeks off and on trying to get fire to the plugs. with no fire to the plugs!!!, took four wires from a heavy duty extension cord and strip the insultlation back to the wire and inserted the wire into the cap and the plugs, and i be dang she fired right up and idle pretty good.

are these wires any good? i took a ohm reading of each wire and all four reads about 0.04 to 0.05. is this a good reading?
if so whats going on with these wires?. thxs for any and all opinions and info. thxs for any input.

Posted: Mon Jun 11, 2012 4:58 pm
by Cacti_Ken
Sounds like maybe the wires/spark are going to ground inside the shield. Did you check continuity from the wire to the outer shield? Would be really unusual for all four to be grounded though.

Posted: Mon Jun 11, 2012 7:31 pm
by circleburner12
ken, i checked the readings from one to the other end of the wire. ive been told they should read zero then ive been told they should read something as long as they all read the same. to be honest i really do not know how to correctly check these wires.

it is really odd for all 4 wires to be bad, i thought the same thing. but i could not get any fire to the plug with them. untill i used the wire from the extension cord. thxs

Posted: Mon Jun 11, 2012 9:32 pm
by wesk
The key I believe is the word NOS. Many old old NOS wires are rotten just from aging. With shielded wiring you cannot see the inner wire and the condition of it's insulation.

There are several ways to check shielded wire for condition.

1-I use a megger and fire enough high tension voltage down the wire that if there is any insulation damage at all it will show as a grounded lead.

2-Using an ohm meter you check the inner wire for continuity from spring tip to spring tip. The meter should read less the 0.5 ohms. Then check for any continuity between the inner wire and the shield. You do this by touching one lead of the meter to a spring tip and the other to the bear stranded steel shield. It should show an open (OL) or no continuity.

3-Disassemble one end of the lead assembly and physically inspect the inner wire.