Okay. I wanna hook up my underbody glow so that it turns on when I unlock my car. First the question:

I got cathodes. Will the dimming feature of the dome lights hurt the cathodes/ cathode transformer?

Dome light trigger is on the negative?

Middle light bulb doesn't have to be in the dome light for the relay to trigger right?

Heres what I was thinking. Attach + Signal on the reay to negative on the dome lights. Ground to Ground. Power source to before the switch for the underbody. and power out to after the switch. So it'd look like this:

^^ Current___________________________________________________________________^^ What I wanna do.
The big black box is the relay. small is the signal.

If the dome lights dont work, could I hook it up to maybe the ring of light for the key hole?

 

You used cathodes for underglow..........??????seem too fragile for that.....

 

- dimming feature hurt? dunno.. don't think so.
- dome light trigger is negative.. yes.
- dome light doesn't need to be on "door" to have it trigger... yes..

circuit seems fine.

 

yea I use cathodes. They've actually held up very well. I've had them on for a year and so far have had no problems with tubes. I was recommended by someone to make the switch and relay on the ground side of the circuit and have the relay and switch go to their own ground points as this would be safer. Sound reasonable?

What if both the relay is triggered and the switch is triggered, So power is going through both the top and bottom routes. Could anything bad happen if that happens?

 

nvm. I did it. Not the way its supposed to be done but it works.