Resistor wire causing problems?

Joined
Jul 11, 2007
Messages
21
Discovered last night that my resistor wire is getting very hot with the ignition on. Tested the wire and came up with a 1.2 reading instead of the 1.8-2.0 that is normal. Obviously need to get a new wire, but could this be causing me problems upstream in my wiring?
 

bruceb58

Supreme Mariner
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Mar 5, 2006
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30,588
Re: Resistor wire causing problems?

This wire is supposed to get hot...especially if the engine is not running.

How did you test the resistance? Did you remove the end on the coil before you made your measurement?
 
Joined
Jun 29, 2007
Messages
58
Re: Resistor wire causing problems?

I'm going to show my ignorance here, but could someone tell me what a resistor wire is? The only wiring I'm familiar with is my own boat, with a '97 Merc 5.7LX. I've never seen one in any wiring diagrams but would like to know so I don't get alarmed if I ever find a "hot" wire.
 
Joined
Jul 11, 2007
Messages
21
Re: Resistor wire causing problems?

I did remove the wire from the coil, and tested from the pin to the coil connector. I realize the wire gets hot, but it was so hot I couldn't touch it for more than a quick touch, certainly couldn't hold on to it. That is what led me to test it and as I said it was 1.2 ohms. I searched for other posts about this wire, and found that if it is over or under spec it is bad, but I couldn't find anything saying whether it can cause problems in the wiring in other areas.
 

Don S

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Aug 31, 2004
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62,321
Re: Resistor wire causing problems?

The resistor wire is used on points type ignitions to lower the voltage going to the coil, which in turns keeps the points from burning up real fast.
 

Robj

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Mar 22, 2007
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Re: Resistor wire causing problems?

If you have a 1.2 ohms resistance and it should be 1.8 to 2.0 ohms, then I would change it. By ohms law v=ir, you are drawing more current at 1.2 ohms than you would be at 2.0 ohms, which may be the reason your wire is getting too hot. But I do not know how those wires work, to me it seems the resistance would increase as they burn out rather than decrease, does not make sense to me. But regardless I would try changing it and see if that resolves your problem.

Have a great day,

Rob.
 

Don S

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Re: Resistor wire causing problems?

but could this be causing me problems upstream in my wiring?

What kind of problems with your wiring are you having? The most that should happen if you have too much voltage to the coil is burned points.
 
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