Help Finding a 12 V Power Supply (1 Viewer)

[1979 FJ40ish]

I’m installing a device in my 79 FJ40 that needs a 12V power supply ONLY WHEN THE ENGINE IS RUNNING.

The wiring is being done as part of a rebuild and I do NOT yet have a fully installed electrical system so there is nothing I can put a test meter to.

I have spent days repairing damage done to the wiring harnesses by PO’s and want to avoid splicing directly into the harness.

I’m not so good with reading wiring diagrams but it seems to me that I might be able to connect to the positive (+) terminal on the ignition coil as a 12V power source.

Can I use this terminal as a source of power or is there a better location that will only have power when the cruiser is running?

Below is a page from my electrical diagram that shows the battery, ignition switch & ignition coil.

 

[1911]

I’m not so good with reading wiring diagrams but it seems to me that I might be able to connect to the positive (+) terminal on the ignition coil as a 12V power source.

Can I use this terminal as a source of power or is there a better location that will only have power when the cruiser is running?

You could, but a better place would be off of the main fuse block.

 

[1979 FJ40ish]

I'd prefer to use a location in the engine compartment if possible. Aside from the fact the line would be fused is there any other reason that makes the fuse block a better location?

 

[1969FJ]

Yes, the fuse block is the heart of the vehicle. That is why there are fuses there. What are you running and what is the potential current draw ?

 

[1911]

I'd prefer to use a location in the engine compartment if possible. Aside from the fact the line would be fused is there any other reason that makes the fuse block a better location?

Well for one thing, I wouldn't want to drain much current away from the coil - that's one reason why this question from @1969FJ is pertinent:

What are you running and what is the potential current draw ?