thinking about lighting up the engine bay (LED) and i wanted to use a 'add a circuit' to access a 12V source in the fuse box.

My plan was to use a fuse that was always 'hot.' I havent tested any to figure out which one that would be but is there anything else I need to know? Recommendations?

Thanks.

 

Everything in that battery compartment fuse box is constant "hot"... So whatever you connect there will require a switch... On the other side of the eng bay is a relay box where you can pick up an ignition activated wire,, I forget what color....

 

The only add-a-circuit I've seen plugs into the fuse block inside the car (the mini-fuses). Do they even make them for the larger fuses and/or relays that you’ll find under the hood?

ciddx,

The easiest way to check for a “hot at all times” circuit is with a test light or a voltmeter. If you don’t have a test light or a voltmeter, you can just pick a circuit that you know is powered all the time, like the horn circuit. If you wire it up to a circuit that's hot at all times, you'll have to install a switch (in your case, probably a hood activated pin switch to turn the lights on/off.

 

Just use the add-a-circuit and hook it up to your Radio fuse, that's what I did with my laser jammer install. No need for a switch, whenever your car turns on, you're good to go. If you want to add a switch (turn off the lights if you want while driving) just splice one in to the power line of the LEDs. Use the same ground spot under the dash and you're golden

You can find what each fuse is from the back panel of the fuse door.

 

If he did that, he would only have light under the hood when the key is in ACC or ON. That's not too useful for a light under the hood.

 

OOOOHHHH wow, yeah totally missed the "engine bay" part of his original post.

 

haha, yeah, engine bay.

Yeah, i have a switch and i want the option of turning the LED on when then car is NOT on. I do have a voltmeter, that was my plan for testing which one was the hot circuit.

@MSCA: I probably should have looked closer, but i thought there were ATO/ATC fuses in the fuse box next to the battery. They do make ATO/ATC add-a-fuse's.