Hi All, does anyone know if the external ignition coil 12v supply from ignition (pink wire) is permanently live when the ignition is on or only live during cranking? I am thinking of injecting 12v to the coil with a feed direct from my battery as I'm not seeing 12v at the pins which feed the ignition coil when the ignition is on or during cranking. I have checked both the ecm (fuse 1) and crank (fuse 3) fuses

Thanks

 

Why not fix the problem instead of placing a bandaid on it ?
power comes from the ignition switch through c100. Find where it’s lost

 

Sorry, I should have given some more context, I ve only just taken delivery of the car and it was working fine last week apparently; so I would like to test to see if that's the only reason why the car has stopped starting hence asking about what the signal should be. I don't plan to leave it wired up this way as a permanent workaround... Only for testing. Thanks

Yes power comes thru c100 connector so I 'could' have issues with the feed from the ignition switch but curious what signal a working car provides please, hence asking. Thanks

 

Typically, I just found this thread by searching again:

https://www.thirdgen.org/forums/tech...-problems.html

Which answers my question.

Thanks

 

The pink wire should have power when the key is in On or Start. Basically any time the engine should be running.

As said, that's a pretty ham-handed way of troubleshooting. It's VERY unlikely that there's anything wrong with the ign sw or the wiring. Other than getting the car out of the middle of the road and to some place safe, useless. More likely, a fusible link has blown, and other things are also not working. If that's the case, then don't mess around with the ignition since that's just a Symptom of The Problem and not The Problem itself, and instead, replace the burned-out fusible link.

 

It was a useful exercise as yes, indeed the 12v ignition source is there but it is the earth wire which manuals state should be chassis ground (a light coloured wire) that is, not grounded. But I can see it's been tapped into another wire that disappears down the bulkhead that I cannot follow from above. I'll investigate in a day or so and run through the workshop guides to test continuity and high resistance / open circuits for a working/healthy coil again. Thanks for the info

 

Never heard of an "earth wire" being needed for a Chevy V8 distributor. Let alone, any "manuals" that state any such. Certainly no factory ones do that.

In any case, the ground wires in these cars, are black, and certain ones that require connecting to specific places due to serving sensitive circuitry such as sensors for the ECM also have a while stripe on their black insulation. There are no "light coloured" ground wires.

The distributor is grounded to the block by being installed. It makes a hard metallic connection from its housing to the block. No wire required. Never has been in any Chevy V8.

Any wires "tapped into" any other wires are a VERY BAD business. Particularly when they're an obviously wrong colour, such as a "light coloured" one being used for ground. Sounds like maybe there's been some hackage inflicted on your poor victim there.