Ignition wiring question
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Senior User
Joined: Jan 2010
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From: South Burlington, Vermont
Ignition wiring question
I'm trying to install a new wiring harness and have an ignition question. With the key switch to 'on' I have 12v to the starter solenoid. I have traced it to the ignition wire to the '+' side of the coil. The '-' side of the coil goes to the distributor. When the points are closed I have 12v to the starter solenoid. When they are open, no power to the solenoid. When the key switch is in the start position I have 12 v to the starter solenoid as it should.
Is it right to have the intermittent 12v to the starter solenoid as the dizzy spins?
I should clarify that I have continuity on these circuits not 12v since the battery is not hooked up yet.
Is it right to have the intermittent 12v to the starter solenoid as the dizzy spins?
I should clarify that I have continuity on these circuits not 12v since the battery is not hooked up yet.
Posting Guru
Joined: Apr 2013
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From: Rimrock AZ
Your starter solenoid should have 4 terminals if it is a remote mount Ford starter solenoid. Battery + in, Battery+ out to starter when the solenoid is energized. S terminal or Battery positive in when the key is in the crank position and the I terminal or battery + out to the positive side of the coil in a negative ground system. The I terminal supplies 12v to the coil at cranking to aid in starting. Hope this helps some. I can't be sure from the description what terminals you are getting your readings on.
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Senior User
Joined: Jan 2010
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From: South Burlington, Vermont
I'm get continuity from 12v battery '+ in' on starter solenoid to 's' terminal on solenoid when key switch is in crank position (just as it should). It also shows continuity when in the 'on' position only when points are made in distributor.
It looks as if there will be 8 pulses to the 's' terminal of the starter solenoid every time the rotor goes around?
It looks as if there will be 8 pulses to the 's' terminal of the starter solenoid every time the rotor goes around?
Posting Guru
Joined: Apr 2013
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From: Rimrock AZ
I'm get continuity from 12v battery '+ in' on starter solenoid to 's' terminal on solenoid when key switch is in crank position (just as it should). It also shows continuity when in the 'on' position only when points are made in distributor.
It looks as if there will be 8 pulses to the 's' terminal of the starter solenoid every time the rotor goes around?
It looks as if there will be 8 pulses to the 's' terminal of the starter solenoid every time the rotor goes around?
Fleet Owner
Joined: Jul 2004
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From: NM
That doesn't sound right. Is your solenoid new? It sounds like maybe it is shorted internally.
Much as I hate to use this (because of the source) this is a diagram of the basic connections. There should be no power to the S terminal in the ON position. If there is continuity, there will be power. (You are using the S terminal on the ignition switch instead of a button, but same concept)
Much as I hate to use this (because of the source) this is a diagram of the basic connections. There should be no power to the S terminal in the ON position. If there is continuity, there will be power. (You are using the S terminal on the ignition switch instead of a button, but same concept)
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Senior User
Joined: Jan 2010
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From: South Burlington, Vermont
Yes, using an ohm meter. I hooked up the battery just to test if it would crank in the on position and it did not. Cranks only in the start position. I don't get it. But it works as it should.
Posting Guru
Joined: Apr 2013
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From: Rimrock AZ
That doesn't sound right. Is your solenoid new? It sounds like maybe it is shorted internally.
Much as I hate to use this (because of the source) this is a diagram of the basic connections. There should be no power to the S terminal in the ON position. If there is continuity, there will be power. (You are using the S terminal on the ignition switch instead of a button, but same concept)
Much as I hate to use this (because of the source) this is a diagram of the basic connections. There should be no power to the S terminal in the ON position. If there is continuity, there will be power. (You are using the S terminal on the ignition switch instead of a button, but same concept)
Sounds like you are hooked up correctly. To further test you could disconnect the lead that goes to the starter then turn the key to the crank position. You should have 12V at the battery in terminal,S terminal, I terminal and the starter terminal. With the key in the on position you should only have 12V at the battery terminal and may have 6-8V at the I terminal that is coming from the positive side of the coil.
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Fleet Owner
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From: NM
Whew! That's a tortuous path! I can see where a continuity tester (buzz-box) would produce the situation.
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From: Rimrock AZ
I use an OHM meter that beeps when I have continuity. I often use it when I cannot see it and just listen for the beep. It messed with me many times when it found a path through a solenoid, gauge or bulb. I now use a power probe almost exclusively, has saved me many headaches. Still use the OHM meter for electronics and coils though.
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From: paradise, northern calif.
This is a great thread, it shows the skill and knowledge of all involved. A well explained question, followed by answers that were to the point, precise, and helpful. I was not only educated by the process, but also very impressed. Well done guys!
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