New resistance wire to coil not resisting???

[philtheskipper]

1979 Mercruiser 120<br /><br />I just ran a new wire from my ignition back to the coil and also used a new resistance wire purchased from Mercury marine(part# 84-94227A2). I have not started the engine yet but when I turn the ignition to the on position I'm still getting 12v at the coil. Shouldn't it only be about 9v whether the engine is running or not? The resistance wire doesn't seem to be working??? <br /><br />If all else fails can I just add a ballast resistor instead and if so what should the exact voltage be at the coil?

 

[gpane]

Re: New resistance wire to coil not resisting???

hey phil<br />i think you should have a resistor bypass which is needed to give 12v when starting then once started the resistor wire kicks in and should see less than 10v, but 12v is needed when you turn ignition to start.

 

[philtheskipper]

Re: New resistance wire to coil not resisting???

Yes, it does have a bypass or jumper wire for when the starter is engaged. I'm talking about when the ignition is in the "on" or "run" position, not when trying to start. Actually, I haven't even hooked the resistor wire to the coil yet cuz I tested it first. So I know the voltage reading I'm getting is coming through the resistance wire alone.

 

[petryshyn]

Re: New resistance wire to coil not resisting???

philtheskipper<br /><br />The resistor wire will not drop the voltage until there is current flowing through the circuit. That means the points must be closed to see the lower voltage at the coil. If the points are open, no voltage loss occurs. If you want to prove this, remove the cap to observe the points and rotate the engine until the points close. Then redo your check...

 

[philtheskipper]

Re: New resistance wire to coil not resisting???

schematic <br /><br />I no longer have points because I replaced them with a petronix module. Does that still apply? If I hook up the wire to the coil will it read the lower voltage or does it have to be running too?

 

[Boatist]

Re: New resistance wire to coil not resisting???

Phil<br />Schematic is right will have no voltage drop on wire until have current flow. On normal system motor does not have to be running but points must be closed. Does Petronix module want you to keep ballast resistor or restance wire?? <br /><br />If you want to test with out running motor then wire your restance wire to + side of coil, take wire off the - side and connect a ground wire. Turn the key on and messure voltage on + side of coil.<br /><br />You could also just hook resistance wire to + side of coil hook up flusher to motor turn water on and start it up. Then again check voltage on plus side of Coil.

 

[philtheskipper]

Re: New resistance wire to coil not resisting???

Does Petronix module want you to keep ballast resistor or restance wire?? <br />

I assume it is ok since they told me it can be used with my coil. The coil would overheat without the resistor, right? It ran fine all last season like that.

 

[Boatist]

Re: New resistance wire to coil not resisting???

Phil<br />I do not know the petronix system, but If any change needs to be made over your old standard I would think that would be clearly pointed out in the installation instructions. I am sure your standard system used resistance wire. I would just hook up your new wire and give it a try. I assume you removed the old wire. What went wrong with the old wire??

 

[philtheskipper]

Re: New resistance wire to coil not resisting???

The old wire started to resist too much. I was only getting about 4 volts at the coil.