Does anybody know of a +12v source when gear selector is put into drive? Looking to add a relay that is only activated when truck is in drive.

 

Maybe DRL lighting? or a negative relay based off rear camera shutting off?

 

Negative relay off your white backup lights might be easier to use ... ?

 

I want the relay to only activate when in drive. I originally tried wiring to the DRL/headlight which at first works. But when you put back into park with engine running, the DRL/headlights stay on.

 

Can you let us know what it is you are trying to activate when driving? You want it activated when the transmission is only in 'D', right? Active when idling at a stoplight?

 

Start with a wiring diagram for the shifter?

 

If you have a floor shifter there is a Park Detect circuit. Will that work for you?

 

I have a column shifter - but I like the idea of that. I am hooking up a more truck sounding horn ( but it's louder than stock ) and I don't want to be that guy waking up the neighborhood when I remote start the truck ( double honk). I want to use the stock horn when not driving.

 

use a different approach. I am in the process of adding truck\train horn (currently researching which one I want) instead of trans in drive detection which is not possible unless you sniff the canbus I am going to use a delayed relay to run the horn.
So I am going to leave the stock horn in place and set the delay relay for 1 or 2 seconds (its adjustable ) to trigger off the horn. SO when a normal horn is required (chirp from alarm or start ) it will run only the OEM horn and when I want to get someone's attention hold the horn down and wait for the delayed relay to kick in and wake the dead.


D.

 

Please let us know which horn you get. I would also like to add a real horn to my 2018.