good place to power relay under hood when truck is on?

Hi, I need a small signal wire to close a relay, under the hood on a 3rd gen 4 cylinder. Does anybody know a good/easy spot that's only hot when truck is running? Thanks in advance

 

Ignition

 

Is there a fuse under the hood for that guy to add-a-fuse onto? Or nice access to the wire somewhere? I was just looking in the bay but nothing really stood out

 

I am mounting a power terminal block in the engine compartment. There are quite a few videos on installing bed lighting on a Tacoma and there are several options. Me, Power distribution block fed from the battery to an in-line fuse. You need to fuse everything supplying voltage to a device. You can open the fuse box and find a signal connection that is controlled by the ignition. Do not hook a device directly to it.
YouTube is your friend in this case. Good luck

 

Im sorry if you can't find the location of this stuff I can't tell you. I don't want you to destroy the thing. Get someone who knows what they are doing

 

Does your Taco have the smaller relay box attached to the Main Fuse/Relay box?

 

Haha, I'm a licensed electrician. I just wanted to avoid tinkering around with a multimeter if there was a consistently agreed upon way to do this , ie for winches, lightbars, etc. All should be relay controlled and fused if the amps that are pulled are high enough. But clearly you either don't know enough to or don't want to help, so be it :^)

 

Yup it's got the little triangle box off the main fuse panel.

 

Which relays are present in there?

 

There's just one, all the way to the passenger side right by where the lid clip is.

 

Like so:

 

Nope, the one above that one in the picture you posted. Mines blue, also.

 

That's the Air Pump Heater Relay. What year is your Taco?

 

It's a 23 4 cylinder. The relay I'm trying to add is just for an inverter in the shell tool boxes.

 

Unfortunately the "only" choice in the engine bay fuse/relay box is the 10A INJ fuse. But it has the quirk that it's tied to a leak test cycle after engine shut down. It might not be an issue for your needs as long as you don't leave the inverter switch ON.

 

Dang. The whole reason I'm going through all of this is so I can leave it on and forget about it while it charges my tool batteries all day while I drive. Sounds like my best option is going to involve taking a wire thru the firewall off of a cab fuse?

 

That would be your next option. But since you are having it on as you drive it's fine. It's the issue of the circuit turning on for a few seconds for the leak test AFTER engine is off.

 

Oh, I totally misunderstood. Thanks for clarifying - so I'd just have a couple seconds of the inverter being on when I shut down? That should be just fine, my charger pulls max 125W, nothing that will significantly affect the battery in a few seconds.

Edit: just googled some info on the INJ fuse. This sounds like exactly what I wanted, thank you very much.

 

You are using this circuit for signal side of relay to supply the inverter, correct?

 

That's correct. Supply side is directly wired to the battery with 1AWG.