DIY: How to add daytime running lights (DRL) to a 2010-2011 Prius

Here’s another mod I’ve performed on the Prius, specifically useful for 2010-2011 3rd gen Prius owners, that’s a spin-off from a past project done on the Acura RSX. I started this mod some time in early May, but got side tracked with the JDM Prius power folding side mirror project and then became inundated with projects at work, causing me to further delay the DIY guide.

With minor modification, you can add OEM-style reduced output high beam DRLs to just about any vehicle using this guide. The concept and wiring remains constant. The only difference is using the correct high beam connector for your specific application. This guide illustrates how to convert your high beam 9005 bulbs into OEM-style reduced intensity daytime running lights (DRL). This mod can also be performed on the 2012+ 3rd gen Prius, but since the 2012+ Prius models already have integrated LED daytime running lights from factory, adding this mod is generally for cosmetic purposes (especially if you use colored bulbs, such as yellow).

However, if you decide not to use the factory LED daytime running lights on the 2012+ Prius, this mod functions as authentic and legal DRL alternative. I personally think high beam converted DRLs are more effective than the 2012+ Prius OEM LED DRLs, since they are mounted higher thus making them more visible. For 2010-2011 3rd Gen Prius owners, this mod will give you the added visibility and safety benefits of daytime running lights. In my personal opinion, this approach of adding OEM-style aftermarket DRL looks 110% cleaner than adding a pair of tacky looking LED bars on the front grill or taping a pair of tacky Christmas-light-looking LED strips on the headlights that both stick out like a sore thumb no matter how you look at them.

If you’re ready to proceed, this project will take approximately 1.5 hours to complete. After experience gained from the Acura RSX DRL project, this guide will be efficiently written and simplified.

As with other DIY guides, common sense and judgement should be used. This guide is written solely for educational purpose only. Neither warranty is expressed nor implied. I encourage you to read this guide thoroughly at least once to assess your capability of performing the mod on your own. If you cannot or don’t have the tools, I recommend you consult with a qualified installer to help you with the install.

Parts Needed

A “Set” means 10 or more quantity of each

• 1x Hamsar 45060 DRL Module
• 1x wire cutter and stripper
• 1x black electrical vinyl tape
• 1x split flex 1/2″ or smaller wire conduit
• 1x set of zip ties
• 1x Philips screwdriver
• 1x set of 14-16 AWG  female quick disconnects
• 1x set of 14-16 AWG T-Taps
• 1x set of 14-16 AWG male quick disconnects
• 2x 14-16 AWG spade terminals
• 1x Single Pole Double Throw (SPDT; 5-contacts) automotive relay
• 1x reel of 14-16 AWG wires
• 1x male 9005 connector with pigtails
• 2x female 9005 connectors with pigtails
• 1x Single Pole Single Throw (SPST; 4-contacts) automotive relay – OPTIONAL
• 1x dedicated push button switch – OPTIONAL

You need the Hamsar 45060 DRL module to begin this project. Without it, you can’t move forward. I recommend looking at their reseller/distributor list on hamsar.com. Doing so will save you some extra cash.

For some reason, the 45060 DRL module is not listed for sale on their web site. I contacted Terminal Supply Co., the fine folks where I ordered the original Hamsar unit for the RSX project in late 2009, just to check and see if they still carry the 45060 module. Sure enough, they happen to have one in stock and ready to ship. I placed the order immediately with them over the phone. Price for the 45060 unit from Terminal Supply Co. is $75.00 plus shipping and tax.

Since the Hamsar 45060 compact DRL module is a solid state relay, no mechanical armature exists to switch electrical circuit. This means that premature failure from worn armature is eliminated and the solid state relay will last for a very very long time.

For added safety and control, include a Single Pole Double Throw (SPDT) relay into your list of parts:

Note: You will need a Hamsar module designed for high beam conversion. A module designed for low beam conversion will not work.

Creating Dummy 9005 Headlight Connectors

The high beams under this mod will be powered directly by the 12V battery. The OEM high beam connector, from the driver side, will function as a trigger to switch between high beam and daytime running lights mode via the Hamsar 45060 module. Because of this set up, we need to make a few mods to the OEM high beam connectors.

In order to wire up the Hamsar 45060 DRL module to your existing lighting system without cutting any wires or connectors from your OEM headlights, we need to create three dummy 9005 connectors:

• 1 male and
• 2 females

When I performed this project on my Acura RSX years ago, pre-assembled 9005 connectors with pigtails were either hard to come by or not cheap, so I had to order the parts from Honda and assemble the connectors myself. These days, you can find them readily available on eBay for cheap. Simply search for “9005 connector.” This is what they look like:

Fortunately, I have some high quality Honda 9005 connector parts and pigtails left over to create a set:

Step 1

Since we are working directly with active wires in this mod, for safety, disconnect the negative battery terminal in the cargo space of your Prius.

Attach an 14-16 AWG female quick disconnect to the power lead wire from each of the female 9005 connector. Connect an 14-16 AWG spade terminal to each of the ground lead wire.

Step 2

Next take a 3-feet of 14-16 AWG wire and attach an 14-16 AWG male quick disconnect two each ends of this 3-feet patch wire. Connect one end of this 3-feet patch wire to the female quick disconnect on one of the two dummy 9005 female connectors. This dummy 9005 female connector will be designated for the passenger side.

Add a 14-16 AWG T-Tap to the power lead of the remaining dummy 9005 female connector, then attach the other end of the 3-feet patch wire with the 14-16 AWG male quick disconnect to this T-Tap.

Your 9005 female connectors should now share a common power source.

Step 3

Remove your OEM high beam female 9005 connectors from their high beam sockets and connect your “dummy” 9005 female connectors in their place. The OEM high beam 9005 connector on the passenger side should be placed in a secure place inside the engine bay.

Mount the ground spade terminal on each 9005 “dummy” female connectors to a metal bolt. Be conscientious with the ground source of choice. I grounded the passenger side connector to what I thought was a metal bolt but turned out it was a resin bolt painted chrome (as seen above – i.e. do NOT ground to the bolt shown on the photo). I spent about 20 minutes troubleshooting and trying to figure out why the passenger side high beam didn’t turn on, checking the connectors, connections, relays, switch and even thought the Hamsar DRL module may have been faulty:

Step 4

Take the female OEM 9005 high beam connector from the driver side and connect it to your “dummy” 9005 male connector with two lead wires:

Attach an 14-16 AWG female quick disconnect to each of the lead wire on the “dummy” 9005 male connector.

Attach one wire to terminal 85 on the SPDT automotive relay. Attach the other wire to terminal 86 on the SPDT automotive relay:

The polarity of the wires going into pins 85 and 86 of the automotive relay doesn’t matter as long as no diode exists in the relay. Most SPDT relays are sold without diode.

Wiring Up the 45060 Module

Here’s the fun part. There are five lead wires extending out of the Hamsar 45060 DRL module. Their color and respective functions are as described:

• BLK – ground
• GRN – connects to ignition-active 12V power source (activates DRL on ACC or Ready mode)
• ORG – connects to low beam wire (deactivates DRL when low beams are on)
• WHT – connects to high beam wire (60% reduced output)
• RED – connects to constant 12V power source

Wiring up the DRL module is straight forward. The BLK wire should already have a spade terminal attached. Let’s trim off excess wires and attach a 14-16 AWG female quick disconnect to each lead wires (WHT, GRN and RED). Add a male quick disconnect to the end of the ORG wire.

Step 1

Add a T-Tap to the positive wire on the low-beam connector from driver side. Connect the ORG wire from the Hamsar 45060 DRL module to this T-Tap. This turns the DRL off when you activate the low beams.

Step 2

Connect the positive wire from the driver side high beam dummy female 9005 connector to pin #30 on the SPDT automotive relay.

Step 3

Connect the WHT wire from the Hamsar 45060 DRL module to pin #87a on the SPDT automotive relay.

Step 4

Connect the ground wire from the dummy male 9005 plug to pin #86 on the SPDT automotive relay.

Step 5

Connect the GRN wire from the Hamsar 45060 DRL module to a 12V source that’s activated on ACC or Ready mode. A go-to wire for this would be the positive wire on any of the auxiliary power sockets.

Step 6

Connect the RED wire from the Hamsar 45060 DRL module to a constant 12V source.

Step 7

Reconnect the battery terminal(s) if you’ve disconnected it.

Testing the Conversion

At this point, your connection should be complete. If you set your Prius to ACC mode, the high beams will turn on within 5 seconds at 60% reduced output. If you turn on your low beams, your DRL should automatically switch off. If you activate your high beams, they should draw power directly from the 12V source you used and illuminate at 100% intensity.

 

At this point, you can wrap up the project and tidy up – or you can continue and add a push button switch.

Wiring Up to an Optional Push Button Switch

If you’ve wired everything as instructed up to this point, then your DRL should operate when you switch your Prius to ACC mode. There is a 5-second delay before the DRL turns on. They will turn off if you turn on your low-beams and switch to 100% high beams if you activate your high beams. The following set of instructions will illustrate how to wire up the Hamsar DRL module to a push button switch.

This is the switch I used, by Top Sage International (source at the bottom of the page):

It fits perfectly in a vacant switch slot on the driver side switch panel:

Assuming you’ve acquired an illuminated push button switch, the switch should have three lead wires coming out of it – similar to a fog light switch. One wire is the 12V input wire, one ground wire and one output wire. The 12V input wire is tapped onto a wire that becomes active when your Prius is in ACC mode. I pick the 12V GRN wire on the auxiliary power socket inside the center armrest console. This wire powers the switch when the Prius is in ACC mode and shuts off when the Prius is off. Accessing this wire is a lot easier than accessing the same socket located on the lower center console. However, the caveat is that getting the plug out of the socket is pretty hard and especially if you have large hands. You’ll see what I mean. To access this wire, you’ll need to remove the center cup holder. Do so by lifting the center armrest and then pushing the cup holder out from below. It’s attached to the center console by four clips.

Technically, you can simply tap the 12V input wire on the switch to this GRN wire and then connect the GRN wire from the Hamsar 45060 DRL module to the 12V output wire on the switch without the additional SPST relay and 15A inline fuse between. I chose not to do this because whenever I work with mods that involve the electric system, I like to safeguard the mod with additional layer of protection; i.e. relays and fuse. If anything goes wrong, the relay or fuse will stop the electric current flow. You can cut corners to save time and omit the additional relay and switch, but I wouldn’t recommend it.

Next, ground the BLK wire and route the 12V output wire through the firewall. If you’ve installed fog lights, you know what to do.

In order to make this work, we need another automotive relay. This time, a 4-contact Single Pole Single Throw (SPST) relay, just like the one used in the fog light installation.

The following connections to the SPST automotive relay will complete the circuit:

• Ground pin #1
• Connect pin #2 to the output wire from the push button switch
• Connect pin #3 to a constant 12V source – you may need to splice or Scotchlok this wire onto an existing wire that’s feeding off a 12V source. Be sure to add a 15A inline fuse between the 12V source and the SPST relay for added protection and safety:
  

  How to add DRL to a 2010-2011 Prius- 15A inline fuse holder

• Connect pin #4 to the GRN wire from the Hamsar 45060 DRL module

Instead of having a 12V-active on ACC mode wire function as the 12V input trigger for the GRN wire from the Hamsar DRL module, we are using the 12V source directly from the battery or an available constant 12V source. The push button switch and SPST relay function as the manual open/closed circuit trigger in between.

Clean Up

Completely optional but this is what I did to ensure a tidy post installation clean-up:

I basically turned the amalgamation of wires from the Hamsar 45060 DRL module and SPDT automotive relay into a simpler and cleaner wire harness that can be tucked underneath the driver side headlight and concealed completely.

I am probably going overboard with this application, but I’ve also diode-isolated all the power wires on the DRL wire harness. This prevents any unwanted back feeding of power.

This is what it looks like after all installation and cleanup:

Wiring Diagrams

To download high resolution print-ready PDF of the wiring diagram, select one of the following:

• Hamsar 45060 DRL module wiring diagram for 2010+ 3rd gen Prius
• Hamsar 45060 DRL module wiring diagram for 2010+ 3rd gen Prius, with optional on/off switch

Troubleshooting

If the DRL do not light up as intended, here are common problem areas to check:

• Check all wire connections and make sure they are secure and correct
• Check ground – almost all problems are due to faulty ground. Ground source need to be 100% metal.
• Check fuses
• Check relay; if you are re-using a cheap relay that was included with an aftermarket fog light kit, you may want to reconsider and purchase a new one. Most of these included relays are cheap quality and the internal armature fail prematurely. You can tell if you potentially have a cheap quality relay if the relay casing has no markings, i.e. amp rating, volt, brand or diagram. I’ve personally had great success with YLE brand of single pole single throw relays.

Where to Buy

• $75.00, HS-45060 DRL KIT / HIGH BEAM REDUCED 60% – Terminal Supply Co.
• $24.95, DRL push button switch – Top Sage International, Co., Ltd / Seller’s eBay page