Bed Lights on a Timer

I'm a biologist and work outside at night a lot, often using the tailgate of my truck as a workspace. My last truck (Dodge Ram) had a topper with a built-in light that was very handy, so when I bought my 2016 Taco last month with a tonneau I decided to add some bed lighting since the cab-mounted light is not sufficient for my needs. I'm also paranoid about forgetting to shut the light off and draining my battery, so I needed to do something about that as well.

I purchased a set of 2 5-foot LED light strips from Amazon (

Megulla LED Truck Bed Lighting Kit with On/Off Switch and Fuse - Super Bright LED, IP67 Waterproof - for Trucks, Trailers, Pickups, RVs, Vans and Cargos (Cool White, 6000K)

https://www.amazon.com/gp/product/B0711FYXSM/) for the light source. I wanted the light to be able to be powered when the truck was off, and there is no constant power source near the back of the 3rd gen Tacos, so I had to run a power wire all the way to the battery. I ran it under the bed along the frame on the driver's side and came into the cab through a rubber grommet under the driver's seat. I then ran it beside the existing wire harness under the sill plate, behind the kick plate, and then through the firewall into the engine compartment through the grommet that the other wires and hood release run through. While the unit is fused, the fuse is close to the lights and I didn't feel comfortable with a long run of wire between the battery and the fuse (even though most of it I ran through a split loom wire protector), so I also elected to add a fuse box under the hood to ensure I didn't have any issues due to a short.

The lights are connected to the underside of my track rails with adhesive. I wanted the switch to be near the tailgate, so I drilled a hole through the side of the bed just behind the track rail on the driver's side, inserted a grommet to prevent chafing of the wire, and ran the wiring through that hole. I wanted to minimize the size of the hole, so I had to take apart the switch to squeeze it through, but in the end I got everything to fit (barely!). I put the switch just under the bed rail a few inches in front of the tailgate.



I didn't want to forget to turn the light off and drain my battery, so at first I planned to install a master switch in the cab for bed lights. That way I would (theoretically, at least) see when that switch was on and could always turn it off and the bed lights would then be off, regardless of the position of the switch in the bed. But then I decided that I might not notice leaving that switch on, plus it would be annoying switching the light on in the bed but then still having to also turn on the switch in the cab. So I opted instead for a timer relay.



I went with this solid-state timer relay I bought off of Amazon (

$35 XDP Small Miniature Timer Delay Relay 0.1 Sec to 9999 Hours, 3V 12V 18V DC 5A, Power On/Off Delay, Cycling, Industrial Control & Hobby

https://www.amazon.com/gp/product/B015Z2EQCU/). It is tiny (just barely larger than a dime) so I pulled out the bed box on the driver's side, wired it in, and then put the box back in after programming the timer. This relay can be programmed in a lot of different ways, from a delayed on, to a delayed off, to actions that require a secondary trigger. I programmed it (after watching some rather less-than-ideal YouTube videos the company promotes narrated by a guy with a Russian accent) to have a 15-minute delay after I turn it on. I checked it with a stopwatch and it is accurate within 2 seconds. So, when I switch it on, the unit will stay on for 15 minutes, then cuts off. To turn it back on I must power the switch off, then back on again.

I think this is the ideal solution for me. It took me a little while to determine how I wanted to set everything up, and the programming was rather confusing, but it all worked out great in the end.

 

I have the same lights and a magnetic switch for my tailgate i've been waiting to install. I like your timer idea! is there any reason you chose to run the power cable through the cab instead of all the way to batter under the truck?

 

I didn't want to come up in the engine bay and expose the wire to more heat than necessary. And I think it's a cleaner install.