Ignition issues Chev

[GavDownunder]

Hi guys, im currently trying to start my new big block chev in a chevelle but having issues.. im a full novice on electrics so be gentle !

The ign switch seems to be either ON or OFF.. and car will start like this but starter stays on.. no power or crank on switch ..I have gone thru a test checking the switch itself and it all checks out ..(new column and wiring )
so as far as I can tell the wiring to the starter relay checks out..

Starter relay -, battery - ground - ign - solenoid ..

When i test power ,the power from battery to relay is good .. turn ign to ON i get power to IGn wire and it will start.. thats before I turn key to crank position.. In keyed ON position it seems i get power thru to solenoid and ign constanly..from OFF to ON.. and I have tried 2 other relays..?

 

[littlespark]

How have you tested the switch?

I take it it’s got 3 connections? The common, the one that goes on when at IGN, and another that goes on when the key is turned further round… and should go off again when the key springs back to IGN.

You might have a sticky relay, but you say they’ve been replaced (have they been tested?)

The power that’s keeping the starter running is coming from somewhere… need to trace back point by point until you find what’s on that should be off.

 

[brianmoooore]

I've seen this a few times where the wire from the alternator has been connected to the wrong terminal on the starter motor solenoid.
In a typical set up, the thick wire from the alternator and the thick wire from the battery should both connect to the outer large terminal on the starter solenoid, but some mistakenly connect the alternator cable to the similar large inner terminal on the solenoid. The engine starts as normal, but then the full output of the alternator is fed directly to the starter motor, keeping it turning.