Convert Turn Signals To Running Light
(and keep the turn signals of course)


Link to YouTube Video Showing Finished Project

Here's another great way to see and be seen while looking stylish at the same time.  You can convert your parking light/turn signal bulb to a dual mode LED called a Switchback.  You can see in the image above how it works (no worries, it'll stop flashing soon) Switchback Bulbsbut here's the wordy explanation.  When you start your engine the white LEDs come on giving you another set of daytime running lights.  When you use a turn signal, the side you're turning to reverts back to a flashing amber.  When the turn is finished and the signal cancels the light goes back to white.  Magic!

The installation is fairly simple, just a matter of replacing your turn signal bulb with the LED, plug the (supplied) harness into the OEM turn signal connector and connect a separate pigtail (part of the harness) to a 12v source of your choice.  You can decide if you want to connect to a source that's powered anytime the engine is running, only when the headlights are on or, for that matter, only when the windshield wipers are working.  Yes, you have a lot of choices.  Most will choose to have the bright LEDs come on anytime the engine is running.  For that, there's a handy relay in the under hood fuse box. We'll get to that during the 'how-to' in a bit.  If your Avalon already has an LED DRL in the headlight assembly (Avalon Limited) this will compliment it and you can connect to that.  If your DRL uses the high beam bulb at reduced power, you'd probably want to turn that off.

What You'll Need

1. A Switchback LED set.  You have options here.  You can purchase individual bulbs online (eBay is one source).  AssemblyThis would require you to build your own wiring harness and purchase resistors to prevent the LEDs from hyperflashing when you use turn signals.  Another option (and the one I chose) is to purchase the bulbs and harness in one place as a plug-n-play kit.   I went to iJDMToy knowing they offer high quality parts and lots of after purchase support if needed.  Here's a link to the assembly that includes bulbs, resistors and harness. You'll need the 7440/7443 option if ordering. There are also pictures and several videos showing installations on various vehicles.  You'll also find many switchback installations on YouTube.

2. Basic tools including a multimeter or 12v test light to confirm a power source for the white light.  Pliers to help remove a relay from the under hood fuse box (if that's where you choose to take your power from).  Small screwdrivers for removing pins holding fender liner and one panel. Ten millimeter wrench or socket, 21mm socket for wheel removal. Small zip ties.

3. Completely optional  wire loom Loom to help make your installation look like it came this way from the factory.  You really don't Optifusewant a bunch of ugly wire hanging around under hood do you? 

A different fuse holder.  Yes, the JDMToy harness comes with a fuse holder but it's one of those old school glass tube type fuses.  Your car uses a low profile mini blade style fuse.  If you use a holder for that same fuse you'll only have to carry a single style fuse in the glovebox.   I found the perfect replacement from a company called Optifuse.  I removed the fuse holder supplied with the kit and spliced the holder shown at right into the line as close to the fuse box as I could get it (photos at bottom of this page).

4. Garage tunes
because there's probably a rule that music must be played while working in the garage.Fender Liner Removal

How To Do It

If you're pretty sure you know how to do this but only need a quick heads-up for the power connection click here.  You'll move right down to the appropriate section.

1. Turn your front wheels
to the opposite of the side you're working on.  If you're replacing the left side turn signal bulb, turn the wheels to the right etc.  This will give you some room to work.

1a. If you're small and still limber
the above will probably work for you.  I ended up removing the entire wheel on each side just to give myself plenty of extra elbow room.

2. Remove fasteners from the front of the wheel well.  There are four of them, all (curiously) different.  One at the top, attaching the inner liner to the fender is a standard plastic keeper.  Pry the center out with a small flat blade screwdriver or a fingernail then remove the entire plug.  Next in line is threaded.  You remove the center part by unscrewing it with a small Phillips style screwdriver then removing the whole plug.  The one at the bottom is removed with a small flat blade screwdriver.  Turn to the left 1/4 turn and pull out the whole plug.  Finally, remove the outside 10mm air deflector bolt (or remove all 3 if you want) under the car that's removed with a socket or wrench.   

3. Pull the inner liner back
so you can see the turn signal bulb socket.  Remove the socket by turning 1/4 turn to the left.  Remove the bulb and replace it with your new LED bulb.  If you're using the iJDMToy harness you'll have to use some pressure and will feel the rubber grommet 'pop' into place.  It helps to use a little bit of lubricant (spelled s-p-i-t) on the rubber to help ease the installation.

4.fastener This is optional but if you remove the (pictured at right) decorative panelPanel that's behind the grill and in front of the radiator it will be easier to run harness wiring across the car.  The easiest and shortest path for the harness is directly behind that panel, just in front of the radiator cap and under the fresh air intake so it really isn't 'necessary' but removal of the panel is simple.  Just lift the center pin of each fastener (pic left) with a small screwdriver then pop the entire fastener out.  With all the fasteners removed you can set the panel aside in a safe spot.  Now you have easy access to run the harness wire across to the driver's side of the car when we get to that step which happens to be........next!

5. Connect the harness to your new bulb.  If you've started on the right (passenger) side of the car (strongly suggested) run the harness toward the driver's side.  Another option here, encase the harness wire in a wire loom.  It really makes the installation look a lot more professional and protects the wire at the same time.  Secure the harness and resistor wiring with small zip ties.  The resistors are only there to mimic the incandescent bulbs you've removed.  Without them you get what's referred to as 'hyperflash' a very fast flashing of turn signals which is the car trying to tell you a turn signal bulb is burned out (lower resistance). 

6. Install the left side LED if you haven't done so already and connect the harness.  Now run the 12V power wire up into the engine compartment toward the fuse box.  Remove the fuse box lid.

7. Now you have some decisions to make.  When do you want the white LEDs to come on.  With engine start?  Only when you need parking lights?  Any time the horn blows?  Ok, kidding about that but there are lots of choices.  Most of us will have the new running lights on whenever the engine is running and that's what I'll show you here.  If you have other plans, use a multimeter or test light to find the circuit that works for you.

8. This is where I save you some trial and error.  You do not want to use the horn relay as might be suggested inRelay some instructions.  That circuit is always hot on the Avalon and when you connect something to the #1 relay pin it completes the circuit.  You know what happens then?  With your head under the hood the horn blasts. Ow!  So, don't do that.  The Avalon does not have an ACC relay (also suggested in some instructions) so that's out. 

What's In?  See the relay in the picture (right) with the white dot?  It's for the cooling fans and that's the one you want if you want the white LEDs to be on any time the engine is running.  In fact, you want your wiring connected to the pin right under that dot.  Remove the relay using a pair of pliers.  It might be stubborn but wiggle it out and don't grab too hard with the tool.  Once the relay is out, route the single wire from your new harness to the plug location we identified and stick a half inch (13mm) or so of bare wire into the socket.  Now put the relay back in place.  It'll go in pretty tight but it'll go inThis is probably the best option for most Avalon owners and was my initial connection.

Note: I've removed the option originally posted here to connect directly to DRL power.  Due to differences between models and a completely different wiring setup between the 2013-2015 and 2016 and later cars there's just too big a chance for mistakes and confusion.

9. It's time to test your handiwork.  Get in the car and press your start button once to put the car in accessory mode.  Take a look at the front of the car.  The new lighting should still be off unless you chose a wiring option that powers up before engine start.  Now push the start button again (you don't necessarily have to start the engine if you're in a closed garage).  The lights should now be on bright white.  Turn on your hazard flashers.  Both new lights should be flashing amber.  Turn off the hazard switch and try each turn signal individually.  One side should be bright white while the direction you're turning should be flashing amber.  Cancel the turn signals and both lights should be back to white.  Hit the start button to turn everything off. 

10. If everything worked it's time to button things back up.  If the light on both or either side completely failed to work there's a very good chance you've simply installed the bulbs upside down.  LEDs are fussy that way.  Just flip the bulb 180 degrees in its holder then test again.  Assuming it's all good, tuck your fender liners back in and replace the fasteners, replace the under hood plastic panel if you removed it, although t tohis might be a great time to replace the stock horn with a Freeway Blaster or other ultra loud horn...ok, another day.  Close the hood.

11. You're done!  Beer

Additional Photos  Click for larger image

This is the driver's side OEM turn signal socket  Turn 1/4 to the left to remove bulb This is the load resistor. Note, I drilled small hole in a frame tab and used a self tapping screw to mount it.  Add paint to the newly drilled hole to prevent rust. All done.  Load resistor mounted, wires all zip tied so nothing can flop around.
This shows the wire loom run just in front of the windshield fluid reservoir and in front of the radiator.  There are a couple of handy holes already drilled for zip ties.  When finished the loom will tuck up under the steel 'shelf' and be invisible.  You can do this without removing the plastic panel mentioned in the 'optional' items section but it's easier without it there.  Fuse box.  Labels show incoming wire loom and the aftermarket fuse I added to be consistent with the low profile mini blade fuses used in the rest of the car.  The little bit of red is the wire tucked down into the fuse box and run to the relay leg.  Note: There are other wires/connections in there that are also powered with the engine running.  Probe around with a test light to make your choice.