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Not getting 12volts from ignition switch

  • Thread starter Thread starter ballajb64
  • Start date Start date May 29, 2009
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ballajb64

New Member
Jul 13, 2006
76
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California
May 29, 2009
#1
  • May 29, 2009
  • #1
Right now i am having a problem in my 1964 1/2 mustang. I am doing a efi swap and i have a harness that i installed. Right now when i try to crank the car there is not 12 volts goin to the ignition wire i used when the key is in crank position. What could the problem be? Does anyone know what color under the dash the ignition wire should be? or does anyone know anything about getting a new ignition switch that has a terminal that stays hot in crank?
 

Edster

Founding Member
Aug 13, 2000
500
1
19
League City, Texas
May 29, 2009
#2
  • May 29, 2009
  • #2
What voltage are you getting? Is the wire a resistor wire of sorts?Most important do you have a multimeter? You can find 'em at almost any auto parts store for around 25 bucks or less. Also one of those continuity tester lights would be helpful. Also check for a bad ground. I had put the battery in the trunk but did not run a ground to the block and had starting issues. Once I didthat it solved my problems. Also check the ground wire that runs from the rear of the block (passenger side) to the body.
 

BarnStang

Founding Member
Mar 2, 2001
1,260
3
39
Hagerstown, MD
May 30, 2009
#3
  • May 30, 2009
  • #3
ballajb64 said:
I am doing a efi swap and i have a harness that i installed.
Click to expand...

WHat harness did you install? If you are doing an EFI swap, then things are going to be a little different.
Is the under dash harness the original factory harness? If so, there is one wire that is switched 12v coming off the ign switch. On the 64 1/2 it should be a red with green strip wire. THat wire would turn into a pink wire which is the ballest resistor wire, then when it passes through the firewall plug, turns back into a red with green strip wire where it goes to the coil +. THat's the factory harness. You sould have 12v into the ign switch on the large yellow wire which should be battery source. Make sure you are getting 12 into the ign sw first. If you don't have 12v on the red with green strip wire in run and start, then you might want to suspect the ign switch. Make sure you have the brown wire connected to the "I" term of the solinoid-this is how you get 12v to the ign in Start. THe resistor wire is bypassed to give the coil a full 12v signal for starting. I'll try to link a diagram.

 
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