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240z Electrical. NO 12v at ignition Switch


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I recently purchased a "ran when parked" 73 with a 350 swap. auto trans. I installed a known good battery and when i turned the ignition switch, the starter would spin but the bendix would not engage. I disconnected battery and then I took a long prybar and taped the starter and starter solenoid.  Reconnected power, then I no longer had power at the ignition switch. 

I have 12.4V at the starter. I have continuity from the "S" terminal to IGN SW BY wire. But I have no 12V at the IGN SW RW wire. or anywhere really. not at the fuse box either. 

I found the a fusible link that is not connected to anything located near the starter. The connector is broken. is this still used in a V8 swap?

Momentarily touching this to the postive starter terminal shows no change.

I am using earlywire.JPG (2800×2031) (airmayer.com) for tracing wires.

Where should I expect 12V when the car is in off? ACC? ON? 

 

I have been staring at this diagram and will be testing W at the fuse box after repairing the fusible link and connecting it to the starter terminal. unless for some reason this is not used anymore. 

 

Thanks for any help. I can use a meter and test light and do have mid level mechanical experience. will get photos up in the morning,

 

Thanks

 

Dondo-Z

 

 

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Edited by Dondo_Z
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  • 4 weeks later...

Turn everything off, put transmission in neutral and spin the crank (via crank pulley bolt) with the appropriate socket wrench (7/8", if memory serves) and either a breaker-bar or a section of pipe engaged with the wrench handle.  Spin the crank for a full revolution.  It is possible that the crank is seized, whence the starter can't muster enough torque to break the seizing.  If the crank is indeed seized, that's problem #1.  If it spins OK by hand, then we'll return to the starter problem.

 

A vigorous person should have no difficulty turning the crank with the spark plugs installed and normal compression.  But if you're struggling, or in doubt, remove the spark plugs (all 8).  With plugs removed, a small block crank should spin with no more than around 25 ft-lb of torque.  Check with a torque-wrench.  If the torque is higher than that, there may be a problem.

 

It may also be worthwhile to try to "start" the engine with the plugs still removed.  Just don't spin it for too many revolutions, as that soaks the cylinders with raw fuel.

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