Coil voltage questions
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Fleet Mechanic
Joined: Nov 2009
Posts: 1,398
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Coil voltage questions
I'm in the middle of a few mods on the dent and wanted to start it up today, since it hasn't run for a month. A freshly charged battery, several minutes of cranking and the dent still doesn't run. I will be checking the coil for spark when it's dark, but, I'm curious, the battery shows 12 volts and the coil shows 6.5 volts with the ignition on. Also, I'm thinking I may have deleted a wire, when removing some of the heater harness. Is there supposed to be a wire to the coil when the starter is engaged?
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
"Ignition on" is ambiguous. There is START and RUN. In RUN, the coil voltage should be approximately half the battery voltage. In START, the coil voltage should be equal to the battery voltage. Your numbers look good assuming the key is in RUN for this test. And yes, there should be a wire from the 'I' terminal of the solenoid to the positive terminal of the coil.
Nevermind the exploration with the multimeter yet, check for spark first.
Nevermind the exploration with the multimeter yet, check for spark first.
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
In "run", the power to the coil runs through a resistor wire. The voltage you see is correct.
When the key is in the "start" position, the coil gets it's power from the "I" terminal on the starter solenoid and gets a full 12 volts.
EDIT: fmc beat me, old age is slowing me down
.
When the key is in the "start" position, the coil gets it's power from the "I" terminal on the starter solenoid and gets a full 12 volts.
EDIT: fmc beat me, old age is slowing me down
.
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