67 Monaco- Blows fuse turning key from off to IGN??

[Billy Spence]

I will do the harness soon, but in the meantime I would still like to drive it a bit. Frustrating as the night before everything was working without issue!

I do have a fire extinguisher handy just in case.

 

[Ross Wooldridge]

All of this runs through the bulkhead connector. When they went bad (and many did), people made some wacky fixes.

You need to check the circuit pathway as per the manual. To do it right, you really should pull the dash harness, check for "repairs", and if you find any, unwrap the whole shebang and check for melted insulation that is allowing wires that should touch to connect and creat problems.

Check the condition of the bulkead too - too much corrosion has its own list of attendent symptoms too which can have these kinds of results.

 

[Davea Lux]

Appreciate all your suggestions. No solution yet.

fixed a bunch of poor condition wires (coil blue wire in pic).

I had another ignition and tried it but no joy. The connector to GND isn’t wired up. Could this be an issue?
Also any idea how to jump this with blade fuses to check if it’s the ign that’s bad?

View attachment 443424

View attachment 443425

!.) The red wire where it is coming out of the harness has no insulation on it, it is probably shorted to another wire inside the taped area of the harness.
2.) On some applications, the GRD connector on the ignition switch supplies a temporary ground to the idiot lights when the switch is in the "start" position. This was a way to test the idiot lights to see if the would light when needed. The case of the ignition switch is grounded to the dash by the mounting collar and the contact to provide a ground to the idiot lights is only active in the start position.

Dave

 

[Billy Spence]

Sorted!!!

thanks to everyone for your help and advice! Short version- bad Earth.

so the faults I had were as described. Then I had more issues like the interior cabin lights not working correctly, doors closed and rear lights off but front footwell on then door open the opposite happened.

traced the ignition block feed and found a live feed from the accessory ignition feed when there shouldn’t have been.

from the shop manual traced it back from accessory to fuse box, couldn’t see anything wrong, turns out it was a broken wire under the box barely, but enough.... just touching the body.

fuse box now fully required and starts and everything works!

just need to reassemble now

 

[thethee]

Way to go!

 

[3175375]

Good work!

 

[Big_John]

Sorted!!!

thanks to everyone for your help and advice! Short version- bad Earth.

so the faults I had were as described. Then I had more issues like the interior cabin lights not working correctly, doors closed and rear lights off but front footwell on then door open the opposite happened.

traced the ignition block feed and found a live feed from the accessory ignition feed when there shouldn’t have been.

from the shop manual traced it back from accessory to fuse box, couldn’t see anything wrong, turns out it was a broken wire under the box barely, but enough.... just touching the body.

fuse box now fully required and starts and everything works!

just need to reassemble now

That's not a bad "earth" or as we call it "ground", that's a short to ground.

Whole different scenario and goes back to the diagnosis of a short after the ignition switch.

 

[Ross Wooldridge]

Glad to hear it's sorted out. Well done!