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Relay - Blue - 4 Terminal - 12 Volt (Qty 1)

Relay - Blue - 4 Terminal - 12 Volt (Qty 1)

Item # 38666-1
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38666-1 - Relays Tow Ready Accessories and Parts
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  • Reviews (60)
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  • Videos (2)
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Tow Ready Accessories and Parts - 38666-1

  • Wiring
  • Relays
  • Tow Ready


Features:

  • Replacement running light/turn signal relay for Nissan trucks and SUV trailer lights and tow package
  • May be required for certain Nissan models that do not have factory-installed tow packages
  • Fits into box under the driver dash to the left of the steering column
  • Limited one-year warranty

38666 Tow Ready Blue Relay - 12 Volt





Video of Relay - Blue - 4 Terminal - 12 Volt (Qty 1)

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Tow Ready Wiring 38666-1 Review

Speaker 1: We're going to take a look at the 12 volt, the blue four terminal relay for Nissan trucks and SUVs, quantity of one. Now, this is a replacement running light turn signal relay for Nissan trucks and SUVs for the trailer lights and the tow package. Now, on some Nissan vehicles, this additional relay may be needed in the in-cab fuse panel to allow the tow package running lights and clearance lights circuit to work. This relay does install in an in-cab fuse back under the driver's side dashboard to the left of the steering column. Now this may also be required for certain Nissan models that do not have the factory installed tow packages. That should do it for the review on the 12 volt, blue four terminal relay for Nissan trucks and SUVs, quantity of one..


Customer Reviews

Relay - Blue - 4 Terminal - 12 Volt (Qty 1) - 38666-1

Average Customer Rating:  5.0 out of 5 stars   (60 Customer Reviews)


- 38666-1
by:

Thought my Titan had a tow package-SURPRISE!! Found etrailer on online forum. thanks so much for the videos! Could use a little help to video for third blue relay,but did know to search for it. Great price,right on time,works erfectly!


Comments
Still working perfectly wouldnt expect any less from you guys
Mr.Ed - 10/11/2016



- 38666-1
by:

Spent countless hours trying to figure out why I didn't have running lights on my new travel trailer. Turns out it was my 2013 Titan. The guys from E-Trailer are my new heroes. They know their stuff. It turned out to be a simple relay that took me 2 minutes to install (and that included taking off the knee apron under the steering wheel). Shipment was quick and part was EXACTLY what I needed. The thing that surprised me was the price. I took the part number and called the local Nissan stealership and sure enough, they had one in stock for [much more]. etrailer's part was xxx and change, including shipping. You guys rock!!!!!!!!!



- 38666-1
by:

Works fine. Locating the existing relay in my 2005 Nissan Frontier was a bit of a challenge. It ended up being located behind the passenger side kick panel as described, but it was not the least bit obvious. The two relays (one brown and one blue) were tightly wrapped in sticky foam and mounted in the bracket there. At first glance the bundle looked like connectors and not relays.



- 38666-1
by:

I cannot attest to the quality of the product but I can say that etrailer.com service is on point. I ordered a relay and it never showed up. Contacted customer service and had a new relay in my mailbox in under 3 days!



- 38666-1
by:

I have ordered several parts from etrailer and have always received great parts for a great price. The support has also been excellent if you have any questions about the parts you are purchasing and troubleshooting.



- 38666-1
by:

arrived quickly



- 38666-1
by:

Received the original package empty with a tear in it. Could have easily happened in transit (or on my door step) but I reached out to support to inquire about how to resolve the issue. Without hesitation I received a confirmation email that an additional part was sent. Love the customer service!



- 38666-1
by:

Absolutely perfect. Had it installed for over a year and relays signals perfectly.



- 38666-1
by:

Than you E trailer for having everything I needed to start towing.. The delivery was on time and packaged very professionally



- 38666-1
by:

great service very knowledgeable in their products



- 38666-1
by:

Very fast delivery thx.



- 38666-1
by:

Great service fast delivery. Just what I needed for my nissan armada to make the running lights work on my trailer



- 38666-1
by:

Worked fine after I found out the factory had plugged the relay pigtail into the wrong socket ! Thanks for your help



- 38666-1
by:

Worked perfect!



- 38666-1
by:

Economy shipping was two-day priority mail. eTrailer is a GREAT place to do business with -- especially with their how-to videos. They were the only dealers that mentioned the extra relay that goes under the dash on Nissan Titans for the trailer towing package!!



- 38666-1
by:

Was exactly right. Thanks


Comments
I bought a kit to put on my truck for the trailer lights to work properly. The parts were perfect for my truck. I would recommend this to anyone with a late model Nissan truck.
Tommy C - 01/28/2021


- 38666-1
by:

Very easy to install. Trailer lights work perfectly now. No idea though why Nissan doesn't already have this relay installed in the Frontier Pick-up trucks.



- 38666-1
by:

Great product and service. Fit our Nissan Armada perfectly and was an easy install to complete the circuit to activate the trailer lights. Much more inexpensive than the dealer offering. Product delivered within days - great communications and service all around.



- 38666-1
by:

Ordered on Sunday and received on Thursday. Very satisfied with the customer service and the quality of the products. We definitely order from here again.



- 38666-1
by:

This product was very simple to instsall and has worked great so far. etrailer made the process of purchasing the item very easy and I am pleased with their service and follow up. Would not hesitate to order from them again.



- 38666-1
by:

I have ordered a couple times and every experience I have had has been great. The site is very easy to navigate, prices are very fair, and shipping is extremely fast. Thank you



- 38666-1
by:

The relay was just as described, with the other reviews and video installation was a "snap"! All of the info was dead on. Thanks


Comments
Works just like it should! Good instructions. Very happy with it. THANKS
K5TV - 07/12/2016



- 38666-1
by:

Very quick delivery and the information you provided on what may be the cause of my no tail light issue helped greatly.



- 38666-1
by:

Works great best price around and easy to install! Will be sure to do business again with you guys.



- 38666-1
by:

Works as described. Now have trailer running lights.


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Ask the Experts about this Tow Ready Accessories and Parts

  • Troubleshooting Trailer Running Light Circuit of 2018 Nissan Frontier Not Active
    On certain Nissan vehicles like yours an additional blue relay is sometimes needed to activate the trailer running lights circuit. This appears to be the case with your 2018 Nissan Frontier since this circuit isn't active. This is a very common issue surprisingly. For the relay by itself you can use part # 38666-1 and the harness you need to access to plug the relay in is indeed located in the cab behind the panel to the right of the passenger's foot panel. It sometimes can be located...
    view full answer...
    Image 1 for
  • 2013 Nissan Titan Tow Package Wiring Fuses and Relays.
    When installing the Factory Style 7-Way and 4-Way Flat Vehicle End Trailer Connector part # N40975 or other wiring harnesses on the 2013 Nissan Titan there are relays that need to be installed. I have included a video showing the exact location of these. If these are in place remove and check the connections for any dust or debris. If this is clear check the connector at the back of the vehicle to ensure it is clean and plugged in fully. If all of this checks out you will need to check...
    view full answer...
  • Everything Works Except Trailer Running Lights After Wiring is Installed on a 2013 Nissan Frontier
    On some Nissan vehicles, including the Frontier, you will need an additional relay, like # 38666-1, if it is not present in the relay harness in the cab of the vehicle. To access the area where the relays will be installed you will need to remove the passenger side kick panel and locate the 12 pin connector that will have the harness plugged into it that the relays install to. See the install video I attached.
    view full answer...
    Image 1 for
  • Running Lights Not Working After Installing New Trailer Wiring on 2015 Nissan Frontier
    This problem is usually caused by the lack of a running light relay. On the 2015 Nissan Frontier, there is a relay harness that must be installed behind the passenger side kick panel. This harness uses two blue relays, one of which activate the tow package running lights, and a larger brown relay for the 12volt battery charge circuit. If the wiring harness you installed did not come with the relay harness, then you will need to purchase a wiring harness with the jumper harness like...
    view full answer...
  • Where to Find Relay that Controls Running Light Circuit for 2007 Nissan Frontier
    If you check out the picture I attached you'll see where to find the location where you'll need to install a blue relay like part # 38666-1. Sounds like you may be missing it as this is very common with Nissan Frontiers like yours.
    view full answer...
    Image 1 for
  • Troubleshooting Trailer Running Lights Not Working with 2014 Nissan Pathfinder
    On many Nissan vehicles like your 2014 Pathfinder, there is actually a third blue relay that needs to be installed in order for the trailer running light circuit to be activated. The running light relay is located in the relay harness behind the passenger floor board kick panel. For the needed relay you can use part # 38666-1. If this does not resolve the issue, please let me know and I will be happy to look into this further.
    view full answer...
    Image 1 for
  • Are Blue Nissan Relays 38666-1 and C57000 the Same Item
    Yes, the single blue 4-terminal relay # 38666-1 is the same as those included in the Relay Kit # C57000. The single part is offered as a replacement when only the one part is needed.
    view full answer...
  • Recommended Relay For 2007 Nissan Xterra With Tow Package And Trailer Running Lights Don't Work
    If you already have the 7-way connector on your Xterra an adaptor should not be needed. What it sounds like is a relay may be missing or may have gone bad. You might check out the attached photo to install or replace a relay. For a replacement relay you can use part # 38666-1. I have attached a photo you can check out that shows the location of the relays.
    view full answer...
  • Where to Install Running Lights Relay on Nissan Frontier
    If the trailer parking/running lights aren't working when connected to your Nissan Frontier then you should just need to add the single Blue Relay # 38666-1 that you referenced. On your Frontier the harness you need to access will be located behind the passenger side kick panel. This is where the blue relay for the running light circuit needs to be installed. I have attached an image to assist.
    view full answer...
    Image 1 for
  • Where is Relay for 2018 Nissan Frontier That Controls Trailer Running Light Circuit
    The trailer running light relay you are wanting to install in your 2018 Nissan Frontier is behind the kick panel to the right of the passenger floorboards. If you fast forward to the 4:10 mark of the install video attached on this page you'll see exactly how the relay installs. The blue relay part # 38666-1 is the correct relay to use.
    view full answer...
  • Troubleshooting Trailer Running Light Circuit Not Functioning on 2016 Nissan Frontier
    Trailer running lights not working with certain Nissan vehicles is a common problem with an easy fix. There is a relay for the trailer running light circuit that is located in the fuse box (in the cab). If that relay is missing or no longer functions then it can be replaced with # 38666-1. The relay of the running light circuit on your Nissan Frontier is in the relay harness behind the passenger floor board kick panel. If you check out the install video I attached the first thing...
    view full answer...
    Image 1 for
  • Trailer Running Lights Not Working on 2012 Nissan Xterra
    The issue is likely the relay for the running lights. The relay is attached to a wiring harness which is located behind the passenger side kick panel near the passenger door (see picture). You should see a harness with 2 blue relays and a larger brown relay. If both relays are there, then the relay is likely bad and should be replaced with part # 38666-1. If you do not see a harness with relays, then it is likely that the harness wasn't installed. Unfortunately this harness isn't available...
    view full answer...
    Image 1 for
  • Where is Relay for Trailer Running Light Circuit of 2016 Nissan Pathfinder
    On many Nissan vehicles like your 2016 Pathfinder, there is actually a third blue relay that needs to be installed in order for the trailer running light circuit to be activated. The running light relay is located in the relay harness behind the passenger floor board kick panel like what you see in the attached picture. For the needed relay you can use part # 38666-1.
    view full answer...
    Image 1 for
  • Where is Trailer Running Lights Relay on Nissan Frontier
    In the passenger side pick panel will be a harness that has a blue relay on it. That is the one that is used for the trailer running light circuit. I attached a picture of where the relay would plug in. If you need a replacement we have the part # 38666-1.
    view full answer...
    Image 1 for
  • Where on 2012 Nissan Armada is Relay # 38666-1 Located
    TowReady part # 38666-1 is a replacement running light/turn signal relay for Nissan trucks and SUVs for trailer lights and tow package. This relay installs in a box under the driver-side dashboard to the left of the steering column. We also offer a 3-relay kit for Nissan models that do not have factory-installed tow packages, part # C57000. This kit includes a brown relay to activate the 12-volt power circuit and two blue relays to activate turn signals. The linked video shows installation...
    view full answer...
  • Relay Recommendation to Activate Trailer Running Lights on a 2005 Nissan Xterra
    It sounds like your 2005 Nissan Xterra is missing one relay (or it has gone bad), that is traditionally found under the dash to the left of the steering column. There is a socket there to plug in the relay that will activate the tow package tail lights. For a new relay the part # 38666-1 would be the correct part number.
    view full answer...
  • Where to Find Trailer Running Light Relay on 2014 Nissan Pathfinder
    The relay of the running light circuit on your Pathfinder is in the relay harness behind the passenger floor board kick panel. If you check out the install video I attached the first thing shown is how to access this area.The correct fitting relay is the part # 38666-1.
    view full answer...
    Image 1 for
  • No Trailer Running Lights On a 2007 Nissan Xterra
    The most common cause we see with the trailer running lights not working on a 2007 Nissan Xterra is the absence of a relay, the Blue 4 Terminal Relay part # 38666-1 which installs into the fuse box under the driver dash to the left of the steering column (see photo).
    view full answer...
    Image 1 for
  • No Running Lights in 2011 Nissan Xterra With Factory Tow Package
    It sounds like your 2011 Nissan Xterra is missing a relay or the running light relay has went bad. You can replace it with part # 38666-1. The relay is normally located in the in-cab fuse panel. You will want to check your particular owners manual to be sure of it's location. I am not exactly sure what you mean by running light hardware but a missing relay is common with the Nissan Xterra from the factory even with the tow package so that is most likely your issue. To be sure that this...
    view full answer...
    Image 1 for Image 2 for
  • Relay Needed for a 2007 Nissan Frontier for Trailer Running Lights to Work
    The relay is located behind the passenger side kick panel in a relay jumper harness. Most of the time this relay does not come with the truck if it did not have the factory tow package and needs an aftermarket relay for towing. If you do not have the relay, then you do not have the jumper harness which is needed for the relay to work. In order to get both the relay and jumper harness you will need to purchase the trailer wiring harness kit that includes the jumper harness and relay...
    view full answer...
  • 2005 Nissan Pathfinder Relay Recommendation for Completing Running Light Circuit of Trailer Wiring
    On some Nissan vehicles there is an additional relay needed in the in-cab fuse panel to allow the tow package running lights/clearance light circuit to work. The relay you will need is # 38666-1. Behind the passenger side kick panel (to the left of where a passenger's right foot would be in the passenger seat) there is a harness that needs this relay installed into it.
    view full answer...
  • No Trailer Running Lights on a 2014 Nissan Frontier
    The most common cause of no trailer running lights on a 2014 Nissan Frontier is a faulty relay part # 38666-1 so this would be the first thing I check. This relay is located behind the passenger floorboard kick panel which you can see in the attached photo. If this is not the issue then please let me know and I would be happy to provide further troubleshooting advice.
    view full answer...
    Image 1 for
  • Troubleshooting Trailer Running Lights Not Working with 2016 Nissan Frontier
    It does sound like there is an issue with the tow package relay on your 2016 Nissan Frontier. The relay for the trailer running light circuit will be located in the fuse box, in the cab of your truck. The running light relay is in the harness behind the passenger floor board kick panel, which I have pictured below. For a replacement relay, you can use # 38666-1.
    view full answer...
    Image 1 for
  • Solution for Trailer Running Lights Not Working on 2012 Nissan Frontier with Tow Package
    Trailer running lights not working with certain Nissan vehicles is a common problem with an easy fix. There is a relay for the trailer running light circuit that is located in the fuse box (in the cab). If that relay is missing or no longer functions then it can be replaced with # 38666-1. The relay of the running light circuit on your 2012 Nissan Frontier is in the relay harness behind the passenger floor board kick panel. If you check out the install video I attached the first...
    view full answer...
    Image 1 for Image 2 for
  • Troubleshooting No Trailer Running Lights on Nissan NV 3500
    The trailer running light issue is not a fuse or relay problem. Because the issue is only when the vehicle lights are on, the ground wire connection is the issue. There are 3 places to check to solve this issue. The ground of the trailer wiring on the vehicle side, the main trailer ground connection to the trailer frame, or the tail lights at the mounting location to the trailer. Each of these connections need to be bare metal to metal free of corrosion, debris, and even paint. You...
    view full answer...
  • Where Would Blown Trailer Running Light Fuse/Relay be On 2015 Nissan Frontier
    Most likely you blew the running light relay of your 2015 Nissan Fronter. One likely place for the relay is behind the passenger side kick panel. The relay is located behind the passenger side kick panel in a relay jumper harness. The replacement you need is the # 38666-1.
    view full answer...
    Image 1 for
  • Trailer Running Lights Not Working with 2012 Nissan Titan
    Since all of the other lights are working with your 2012 Nissan Titan then it could possibly be a blown or missing fuse or you will need to add or replace a relay. Use the truck owners manual to find the locations of all fuses and relays related to the tow package wiring. If it is a relay it is likely the one on the in-cab fuse panel and you would use relay # 38666-1.
    view full answer...
  • Trailer Running Lights Relay Location on 2013 Nissan Frontier
    Trailer running lights not working with certain Nissan vehicles is a common problem with an easy fix. There is a relay for the trailer running light circuit that is located in the fuse box (in the cab). If that relay is missing or no longer functions then it can be replaced with # 38666-1. The relay of the running light circuit on your 2013 Nissan Frontier is in the relay harness behind the passenger floor board kick panel. If you check out the install video I attached the first...
    view full answer...
    Image 1 for

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Info for this part was:

Employee Mike L
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Employee John H
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Employee Adam R
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Employee Jeffrey L
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Employee Sarah H
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Employee Andrew K
Video by:
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Installed by:
Jeff D
Employee Nicholas E
Test Fit:
Nicholas E
Employee Chris R
Video Edited:
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