Underhood Fuse Question

kheeney · March 15, 2016

Today I installed some LED lights in my bed so I can see under my cover. They came with a 4 amp fuse to wire directly to the battery.

I decided to use an "add a circuit" to splice it in to my underhood fuse box. I chose the fuse labeled "misc ignition" it had a 10 amp fuse in there already. (I think it was fuse 44).

I pulled the fuse to see if I could figure out what it is used for. It gave me a message to "service trailer brake controller" when I turned the ignition on, so I'm guessing that it powers that, and according to the owner's manual (I later found out), it also powers cruise control.

Question:

-The "add a circuit" says max 10 amp, is this for one of the slots or for both combined? I left the 10 amp for the ignition in there, and put a 3 amp in for the lights, is this over powering it, or should it be okay?

My LED switch only draws 15 mA to stay always on, so I might just wire it directly to the battery so I don't have to have the ignition on to use the bed lights. Assuming this wouldn't kill my battery?

dsatwork · February 12, 2019

So how did this work out for you, did you use the eng misc fuse or go direct to the battery with and inline fuse?

carnau · February 13, 2019

7 hours ago, dsatwork said:

So how did this work out for you, did you use the eng misc fuse or go direct to the battery with and inline fuse?

The misc ign controls the ABCM, TCCM, Stop lamp Switch, Climate Control module and rear view camera.

If you're going to use this fuse I recommend using the add a circuit that has the 2 fuses and use the proper fuse. Like this one (https://amzn.to/2IbbQ9M )

Here is a Misc Ign schematic if you want to see what exactly it controls on your vehicle and the RPO codes to tell you.

dsatwork · February 13, 2019

Thank you for the info, it may be very helpful if I ever have an issue with that fuse. I tapped it tonight and everything works great. Thanks again. Dave