Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.
Error submitting comment. Please try again momentarily.
When your trailer and tow vehicle use different connector styles, this adapter makes them work together. The Custer Trailer Connector Adapter plugs into a 4-way round socket and gives you a 4-way flat plug. It keeps the same wiring functions—running, turn, and brake lights—so your trailer lights operate just as they should.
Instead of cutting or splicing wires to make mismatched connectors work, this plug-and-lead adapter connects right up. Just plug the round end into your vehicle’s 4-way round socket and hook your trailer’s 4-flat plug into the other side. It’s quick, clean, and ready to tow.
The adapter is designed to fit standard 4-way round receptacles like the Pollak Heavy-Duty 4-Pole Round Pin Socket. It includes three larger pins and one smaller ground pin opening, matching the traditional layout so you get a snug, solid connection every time.
Whether you’re connecting a utility trailer, lighted accessory, or tow lights with a different connector type, this universal-fit adapter keeps things simple. It’s a straightforward way to make sure your equipment stays powered and visible on the road.
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Today we are going to be reviewing Part# ADP001. This is the Custer Trailer Connector Adapter, four-way round to four-way flat. So it's going to convert your round trailer connector to a four-way flat trailer connector. It's got the nice easy-to-use pull grips. It's going to make the plug easy to install and remove. This is going to made from an ABS plastic construction, very strong, durable, and long-lasting.
If we take a measure of the approximate length, measuring from edge to edge, it's going to give us a measurement of about 3-1/2, 3-5/8 of an inch, somewhere right around there. It's really to simple to install. This end right here is going to plug into the four-way round connection on your vehicle. Then, on the back side of that, it's going to expose the connection point for the four-way flat connector. That's going to do it for our review of Part #ADP001. This is the Custer Trailer Connector Adapter, four-way round to four-way flat.
.
Customer Satisfaction Score:
94% were satisfied with this product
6% of customers were not satisfied
Ratings & Reviews
Received. Thank you very much!
Tried it and it fit perfectly...
ok
Fast service very good
just what i needed
A great product.
ITEM ON ROUND END WAS LARGER THAN ROUND SOCKET ON TOW VEHICLE. DIDN’T FIT.
Great product, worked just as expected. Thanks
Great product.
did not fit the female end so I tried to grind it down a little and it is no longer useful - probably would have been ok if it fit
Works as shown. It is hard to push into the Pollak socket on the vehicle and seems a little flimsy...have to be gentle with it.
Wonderful sight too easily order from with fast fast delivery and great prices! Thank you for this great product
We plugged it in and it works great. Still working great a year later. Very happy with our purchase.
The round end will not fix the round socket on the truck. It was made with too large a diameter. Tried to find a socket that it would fit at several auto parts stores and at U-Haul main store and none had one that would fit. Bummer. It's of no use.
Works as it should/ described. Fast shi pping
My stock wiring plug receptacle (4Round) on my Fleetwood Motorhome is not wired the same. Could not use it for my application.
This adapts to the "heavy duty" round outlet with one thin and three thick pins (fits my '95 Lazy Daze). Round outlet's lid/latch engages correctly. Flat side relies on friction. Molded housing seems strong and fits snugly.
Note: some descriptions say "length = 4 ft". That should be 4 inches.
I purchased a $5 adapter on a Sunday and paid $25 for 2nd day air and didn't get my adapter until Thursday late evening... Sure, I bought from etrailer before and no problems but this sounds like a rip-off. I will sureply accept my shipping money back. 4 business days later is not 2nd day air.
If you are looking for a 4-round to 4-flat adapter that fits the "heavy duty" 4-round plug, which seems to be rare, this is the adapter you're looking for. The pins on the "heavy duty" four-round plug are wider than the standard 4-round.
Great product, just what I ordered.
I couldn’t find this adapter anywhere else until I came upon it at etrailer.com!!
I have ordered other products from etrailer and have been completely satisfied with those products as well. Thanks.
Do you have a question about this Custom Fit Vehicle Wiring?
Info for this part was:
At etrailer we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.
Brooke M.
3/8/2024
I am sorry to hear that! This type of 4 pole round plug is very outdated and only seen on older trailers and vehicles. I have heard of older ford trucks having a smaller 4 round plug receptacles on their trucks. I wonder if that is the adapter didnt fit? Since the adapter didn't work, your only option would be to rewire your truck with a new 4 flat. What's the year make and model of your vehicle? Would you be able to email me pictures of the port on your vehicle?