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  • 1965 - 1973 Classic Mustangs -General/Talk-
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Understanding coil power curcuit

  • Thread starter Thread starter GT350R
  • Start date Start date Dec 20, 2007

GT350R

Member
Oct 5, 2000
723
0
17
Cleveland
Dec 20, 2007
#1
  • Dec 20, 2007
  • #1
lets try this here. The guys at VM dont seem to like me.

Ok , stareing at this for a while now. Trying to " get it".

Making my own harness and was not planning on having a conventional starter relay. I was going to use a power distribution , and a mini starter instead.

Now I am an EFI guy in background and the later starter relays dont have this second pin on them where the brown coil wire plugs into.

So I see the wire starts at the ignition switch (C terminal, correct?) , then goes to the main disconnect where it splices off and goes to the coil. The other side of that splice goes to the starter relay.

I am about to elimnate the whole curcuit and tie it in with the fuel pump relay , triggered by a switch. But I would rather have the fuel pump relay an the coil work with just the key.

I guess I just need to know if its purpose of attaching to the starter relay is if the ignition switch terminal does not provide power while cranking. If not, what am I misunderstanding?
 

Tim65GT

Active Member
Feb 24, 2004
1,149
2
39
West Texas
Dec 20, 2007
#2
  • Dec 20, 2007
  • #2
It gets reduced voltage (6~9V) from the ignition switch through the resistor wire.

When cranking, the solenoid provides full voltage to the coil for firing up.

If you have an aftermarket ignition system, most of them bypass the resistor wire and run directly from the full system voltage. In which case you can get rid of the wire from the solenoid.

The coil and fuel pump can draw a significant amount of current, I would run it off it's own relay triggered from the ign. switch.

I would also use a small relay to for the mini starter solenoid. There was a thread on that a while back...

http://forums.stangnet.com/showthread.php?t=722355

And good stuff here:

http://forums.stangnet.com/showthread.php?t=667850
 
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