Need a Wire w/ Key on Power & Power During Cranking

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fenderman33

fenderman33

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Would someone point me to a wire under dash that has 12v only when the key is on and when the key is in the crank position.
1972 Dart 318.
Thanks,
Jon
 
yellow wire from ignition switch to starter relay is 12 V only in crank position.
 
I had to have a hot wire during cranking for my electronic Autometer speedo to "initialize" correctly. I tapped into the back side of the stock fuse block (likely the battery feed in pic). A test light will tell you which stay hot during cranking. Generally speaking, none of the accessory circuits are hot during cranking.

fuseblock.jpg
 
To clarify, it needs to be hot with the key on, hot with the key in the start position, and no power when the key is off.
It's to run the main control relay for the megasquirt, so it has to cut off with the key off.
Thanks,
Jon
 
You need to double check with a test light but I only have power to my speedo in the start and run positions.
 
I just went through the back of the fuse box with the test light and there's only a constant voltage wire and the accessory wires.
Any other ideas?
Thanks,
Jon
 
Sorry - you're right. I had to go back and check my correspondence with Autometer. The solution to my issue involved power in the run position and making sure there was no power during crank. I connected to one of the accessory circuits to effectively kill all power to the speedo during crank.

Getting old sucks. Sorry to waste your time.
 
Autometer Megasquirt speedo ,
yeah I'm with ya
NOT
 
Should anyone else run into this issue...

I ended up putting one key on power wire and one cranking power wire together to trigger the relay and used a capacitor to keep it from cycling off and then on between run and start. I don't know how anybody else is doing theirs, but this works for me.

-Jon
 
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