Occidentalis

Hi all,
Trying to add lights that come on when the dome/interior lights come on in my UK built 2006 CR-V EX 4x4. The lights are hooked up to a relay that has separate switch control, so I don't need the amp draw, just a typical small gauge wire. I need to find the wire or fuse that becomes hot (or negative toggle) when the interior lights come on.

There are two options I believe
- one under the dash vehicle and
- one under the hood. https://honda-tech.com/forums/honda-...relay-3239379/

Does anyone have any experience tying into these lines? I haven't busted out the volt meter yet, but I'm thinking that the under-hood is always hot, and the negative (green wire under the dash) is what I'm looking for. I think I can just tie this into the negative from my switch, so that it performs like I want. Does this sound right to you guys?

Thanks, as always, for the help. You guys are great!

For anyone interested, these are the lights I'm adding, to illuminate the ground around the vehicle when doors are opened. I have the OEM side steps and there are plenty of good places to mount them.
Universal LED Rock Light Kit | Rough Country Suspension Systems®

Occidentalis

So, my father and I have been looking into this - here's the diagram from the electrical control manual:




The rear light is operated by the tailgate and hatch glass latch. It is not on a timer and powered directly by vehicle power. i.e. it’s not controlled by a computer module. Thus, the light goes on when either is opened and off immediately when closed. It is separate from the front light.
The front doesn’t go on when the back is opened in any way. If the back glass in unlatched, the wiper won’t work.

The front ceiling light is controlled by three things, all of which are inputs to the Multiplex Control Unit (body computer). The inputs are remote door unlock, driver door, and all the other doors (not the rear stuff, just the passenger doors). The door switches are just logic inputs to the Body Computer. Meaning, very low voltage and current.

What it indicates is that the front and rear dome lights are controlled separately, and don’t go on at the same time. They may both be on for a while because the front is on a timer after the passenger doors are closed.

This may make it difficult to get this to work so that the lights turn on when any opening is opened.

Occidentalis

Sorry for the triple post, but I like documenting things so that if other people have the same questions they don't have to tear into circuits like me. Here are the internal switch workings of Rough Country's 4-piece LED Rock Light Kit - 70541

tech8

The dome light is negative trigger from the door switches, each door switch wire run to the Multiplex Integrated Control Unit (MICU) located in the under-dash fuse/relay box. If you connect the ground source wire from your LEDs to the wire from the MICU, it will trigger the your LEDs to come on when a door is open and shut off with the doors closed after a brief period.

It is the Grn/Red wire (which is a wire with green colored insulation and a red stripe running through it) coming from the MICU that supplies the ground to the ceiling light.

Occidentalis

Thanks - just for clarification - can I connect the black ground wire from the switch line to the MCU red/green - not the main thick black ground wire that goes to my fuse block - and get that result?

And just adding more documentation for the Rough Country Rock light kit - here is the relay with the shrink wrap removed. The blue wire is the switch and white is constant power. The rest of the red and blacks are self explanatory.

tech8

You would be connecting the LED's black ground wire to the Grn/Red wire coming from the MICU.

Occidentalis

There are two black ground wires, one off the switch (low amperage) and one main negative ground. It sounds like you're telling me to dump the potential 20-30 amps off the relay into the grn/red wire, I don't know if I'm comfortable with that.
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