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12V cranking tap point

 
Old 06-11-2019, 05:14 PM
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my74ls4
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Default 12V cranking tap point

All,
I just got finished pulling the ZZ502 out of the 74 and installed the 454. Having starting issues that are driving me nuts. First the starter operates fine, it is a high torque mini starter that I had on the ZZ502. There is a relay on the "S" terminal of the starter and the relay connects to the "+" side of the coil to provide 12V during cranking. I am only getting 8V during cranking now for some reason. I got lucky with the cam break in as once I let the ignition switch go to run the engine ran. I have a connection coming from the "ACC" terminal on the fuse box that provides the 12V in the run position. Tired of trying to determine why I only have 8V during cranking. All connections look good. Is there somewhere I can get 12V from during cranking? Was wondering if the "IGN" terminal can provide this. If it does I can simply move the ACC connection over to the IGN terminal. Hope this makes sense. Thanks
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Old 06-11-2019, 05:48 PM
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MelWff
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The IGN normally provides full battery voltage.
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Old 06-11-2019, 07:12 PM
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69427
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Originally Posted by my74ls4 View Post
All,
I just got finished pulling the ZZ502 out of the 74 and installed the 454. Having starting issues that are driving me nuts. First the starter operates fine, it is a high torque mini starter that I had on the ZZ502. There is a relay on the "S" terminal of the starter and the relay connects to the "+" side of the coil to provide 12V during cranking. I am only getting 8V during cranking now for some reason. I got lucky with the cam break in as once I let the ignition switch go to run the engine ran. I have a connection coming from the "ACC" terminal on the fuse box that provides the 12V in the run position. Tired of trying to determine why I only have 8V during cranking. All connections look good. Is there somewhere I can get 12V from during cranking? Was wondering if the "IGN" terminal can provide this. If it does I can simply move the ACC connection over to the IGN terminal. Hope this makes sense. Thanks
Have you got a picture or a wiring diagram of that setup? That's something different from anything I've seen.
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Old 06-11-2019, 08:06 PM
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'75
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Acc does not have power while cranking, only when the key is on or in acc, but not start. Ign has power in on and start.
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Old 06-11-2019, 08:26 PM
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Richard454
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Here you go-


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