Intro: Under Dash Lighting
Create a unique feel to the inside of your vehicle with these simple and inexpensive steps.
Step 1: Gather Supplies
What you will need:
-Two or more LED light strips
-5-10ft of red and black 16-18 gauge automotive wiring
-Black electrical tape
-10 amp inline fuse
Step 2: Find Fuse Box
Find the fuse box in your vehicle. This should be inside the car somewhere. In most vehicles it will be on or around the dash in some manner. Some common places to look are: on side of dash on drivers side with door open, on side of dash on passenger side with door open, inside glovebox, under dash near pedals, and on some imports such as BMW in the trunk near the battery could be a possibility.
Step 3: Choose When You Want Lights to Be On
The under dash lights can have different settings of when they are turned on. One way is to have them come on with the parking lights/headlights. The other way is to have them come on when the vehicle is started, and shut off when the vehicle shuts off. In either situation, the wiring is almost the same.
- To come on with headlights:
- The fuse for this can sometimes be a little tricky to locate. The goal is to find the fuse that already controls the interior lights of your car. This can be labeled many different things such as, Gauges, Interior Lamps, Dash, Lights, ect. Look for something that resembles these.
- To come on with vehicle:
- This method is more straightforward than the earlier one. Again there is more than one fuse that can be chosen for this method. One option is to put it on the same fuse as the radio, which means whenever the radio is on, the lights are on. Another option is to use the fuse for the ignition, which means whenever the key is turned on and the car is running, the lights will also be on.
When choosing either of these two methods, all that is required is to splice into the wire to that fuse. By using a multi-meter locate the hot side of the fuse. To do this, simply use the black probe of the meter to stick to a grounding part of the vehicle, and the red probe to the fuse. Place the red probe on one side of the fuse while it is still in the fusebox. If no voltage is detected, then test the other side. Whichever side does NOT have voltage is the side that you will splice into. NOTE: the key must be in the on position for this procedure. Locate the back side of the fuse box and the wire coming out of the side of the fuse, and splice your wire inline with this wire using a connector. The reason for putting it on the dead side of the fuse is to allow extra fire protection.
Step 4: Locate a Grounding Point
Locate a spot under the dash of the car that you can use for a ground. The ground is one of the more crucial steps in this process. The most likely place will be the firewall. The firewall will be located under the dash of the car, separating the engine bay from the inside of the vehicle. On the firewall there will be multiple spots where parts are bolted to it. By removing one of these bolts and using a connector to slide under the bolt, you can form the ground. Be sure to tighten the bolt back down securely.
Step 5: Add the Inline Fuse
For the red wire that you now have connected to the fuse, you need to add another inline fuse to this circuit for added safety. Connect the fuse inline as close as possible to where it is connected to the fusebox.
Step 6: Connect Wires to LED Strips
Connect the wire that you have connected to the fusebox and the wire connected as a ground to the first of two LED strips. While splicing this together add another set of wires to this connection to run to the second LED strip. Once this connection is tight run the wires over to the other side under the dash and connect the other strip.
Step 7: Test
Now would be a good time to test everything before you make the final adjustments . Depending on which way the lights are wired will alter the procedure of testing slightly. Turn them on in whatever fashion they were wired, if they do not light up there are some steps for troubleshooting at the end of these instructions.
Step 8: Mount LED Strips
At this point you should have decided where exactly to mount the LED strips. The most common place is on the plastic under the dash. NOTE: Be sure to account for where the wiring will go before this step! Be sure to route it so it can be hidden, and so it is out of the way of any moving parts such as the steering column and pedals. Remove the paper covering the adhesive and stick the strip to the surface. Be sure to hold it for at least 60 seconds to allow the adhesive ample time to set up and bond the the surface.
Step 9: Tidy Up Wiring
This is the time to tidy up all of the wiring going to the strips. Zip ties are a good tool to keep the wiring out of sight. A good way to do this is by tying the wires into the existing wiring harness in a vehicle. Most vehicles have a piece of the body wiring harness running through under the dash. If this is not available, any part of the dash will also work. Anything that will not allow the wires to get tangled into any moving parts will be fine.
Step 10: Troubleshooting
- Lights will not turn on
- Check Fuse
- Check all connections for tightness
- Check connection to that strip
- Check that LED strip is still good by hot wiring straight from battery
Step 11: Disclaimer
Aftermarket lights inside a vehicle are strictly prohibited in some states and counties within those states. Be sure to check with local law enforcement agencies before making any modifications to the inside of your vehicle.