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

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

Item # 38666-1
Our Price: $12.62
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Shipping Weight: 0.05 lbs
38666-1 - Relays Tow Ready Accessories and Parts
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  • Reviews (62)
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  • Why etrailer?

Tow Ready Accessories and Parts - 38666-1

  • Wiring
  • Relays
  • Tow Ready


  • 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 4 Terminal Blue Relay Review

We'll be using a Tow Ready relay, part number 38666-1. Here on the driver's side to the left of the steering column will be three relay connection points. Two connection points already have the blue relay installed. For some applications, we will required to use a third blue relay. This third blue relay will activate the brake signal circuit for our connector. To make it easy to get to the relay connection point, we'll remove the kick panel.

To remove the kick panel, we'll remove the two screws at the bottom to secure it and then pull up and out releasing the fasteners underneath. We will go ahead and install the third one, which will be on the top of the three. Now with the relay installed we're ready to hit the road and that does it for the install of Tow Ready relay, part number 38666-1.

Customer Satisfaction Score:

Customer Reviews

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

Average Customer Rating:  5.0 out of 5 stars   (62 Customer Reviews)


Excellent customer service


Great website that makes it easy to find just what I need.


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!

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


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!!!!!!!!!


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.


I cannot attest to the quality of the product but I can say that 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!


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.


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!!


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.


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.


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


Works great. No issues. Fixes trailer tail lights on non factory install.


Works as described. Now have trailer running lights.


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

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


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!


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.


Simple fast service. The how to install instructions were easy to understand. Great product for the after market towing for my Armada. Thanks etrailer!!!


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


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


Product arrived quickly and in great shape. I was notified when item was processed and again when it was shipped. This is not my first purchase and will not be my last. Thanks etrailer.


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


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


Thanks again for the great service and prompt delivery. Your tech support is wonderful.


great service very knowledgeable in their products


arrived quickly

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