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Tail Light Isolating Diodes (Qty 4)

Item # 48955

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  • Tow Bar Wiring
  • Diodes
  • Hopkins

Hopkins Accessories and Parts - 48955

Allows motorhome or R.V. to power the lights on the towed vehicle without power feedback.

  • Includes 4 Isolating Diodes
  • May also require the 4-pole wiring harness or vehicle-to-vehicle converter (see related products below)
  • Max amperage: 3 amps
  • Max voltage: 24 volts

Note: If vehicle being towed has amber turn signals (separate turn and brake signals) then the vehicle to vehicle tail light converter (118158) will also be needed.

Product detail

Tail Light Isolating Diode System by Hopkins Manufacturing

48955 Tail Light Isolating Diodes (Qty 4)

48955 Tail Light Isolating Diodes (Qty 4)

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Video of Tail Light Isolating Diodes (Qty 4)

Videos are provided As a guide only. Refer To manufacturer
installation instructions And specs For complete information.

Video Transcript for Tow Bar Wiring Diode Installation - 2011 Jeep Liberty

Today on this 2011 Jeep Liberty, we are going to install part number 48955. First off, what we are going to do for our wire harness is find a spot where we are going to locate the 4-pole end. And you can do it anywhere you want. We are going to actually run it to the center on this vehicle right here for now. Put it over this pin. And then we will go ahead and start routing our cable from the front of the vehicle all of the way back. Just stay away from anything moving, like the suspension components, or anything hot, like the exhaust. OK, we will take our ground wire with the ring terminal and we will run it straight to the frame. We will go ahead and show you how we routed our wire. Above the sub-frame there is a piece of tubing that goes all of the way across the suspension. So we actually thread it through from the front to the rear. It is actually easier to see from the back side right here. And then we were able to run it through the frame, using the wire pull. We were able to go all of the way out to the back of the vehicle. We were also able to route it through the back cross member. Our green and brown wires go over to the passenger side of our vehicle. And our yellow and brown wires will go over to the driver side. 1:02

Alright, next we will go ahead and remove the taillights of the vehicle. We will start off with the driver side and then do the passenger side. We are going to tape into our wires to install the diodes. So we will go ahead and take away the protective covering right now. We will be looking for two circuits. We will be looking for the brake circuit and the running light circuit. Now the reason we are looking for the break light circuit is that is going to do two functions for us. The break light circuit is going to do the break light, of course, and also the turn signal since it will be combined coming off of the RV. That allows us to use two less diodes and less wire splices. And the running light circuit, of course, will be dedicated to the running light. So we will test our socket. And that looks like white with a light green stripe. So that will be our running light circuit. So we will cut our wires in half, add our connectors to them and then we will install the diode in between. Now, when we install our diode, there is a label on there that say out and two inputs. Our out will always go towards the taillight. So we will slide that on. And then our input from our vehicle wire harness will go on one of the tabs. It does not matter which one. 2:05

Have somebody else hold the brake pedal. OK, that looks like a dark green wire with a white stripe. Do the same thing as before. Cut it in half and add our diode. Alright, we are going to take our wires, the yellow and brown, and we are going to pull them up from the bottom up here and connect those up to our diodes. And we will use a zip-tie to hold it in place. Then we will go ahead and shorten our wire to match up to our diodes. OK, we added our terminals to the wires. Now the yellow wire is going to be our brake and turn signal. So that will go to our diode that went to our brake signal. And then our other diode will be the running light circuit. So the brown wire will be running lights. All we have to do now is just bundle everything together. And then just reinstall the taillight and we will move over to the passenger side and do the same thing once more. 2:56

The white wire with purple stripe will be the running light circuit. And our brake signal looks like it is going to be the white wire with a light green stripe. We will go ahead and pull our green and brown wire up. We will zip-tie it off and cut it to length. Our green wire will go to our brake signal circuit. And our brown wire will go to our running light circuit. Alright, and then we will just bundle everything back up and reinstall the taillight. OK, with that that will finish our install of part number 48955.

Customer Reviews

Tail Light Isolating Diodes (Qty 4) - 48955

Average Customer Rating:  4.8 out of 5 stars   (57 Customer Reviews)

- 48955

by: Jerry L.08/04/2011


- 48955

by: Stan Jernigan05/30/2014

The diodes were received as promised, however, It may turn our to be a mistake on my part. These parts were ordered so I could hook up lights on my 2014 Cherokee Trailhawk so that it could be pulled behind my motorhome. After running wire from front to rear and getting the wire up to the taillight area, I found that the wiring on the Jeep was much smaller than what I had worked with on previous mods of this type. I feel that I may have to splice extra wire into the system in order to complete this installation. If you have any additional information on how to make this work on a new Cherokee, please share it with me. Thanks for your interest. Stan Jernigan 133505

- 48955

by: Jim02/06/2013

not good quality control .installing the diodes on a honda CRV. No room in taillight housing so had to remove inside trim and find supply harness and installed there. Checked and everthing, ok. Hooked up to motorhome an re checked one light would not work. removed trim one more time. replaced connectors re check the discovered when wiggling wires light would blink. One tab on diode had a intermitant contact inside diode. waiting for a relacement? 65139


You replaced the bad diode contact on wiring tap had intermitant contact everything is ok and has worked flawlessly for a year. Thanks for the good service.

-- comment by: Jim - 02/10/2014

- 48955

by: John A08/26/2013

I received the diodes this AM & installed them a couple hours later. Checked them out & they work as advertized. Everything went fine with the order except I was never given any tracking info. It was shipped the day I ordered & I received it a week later. I was beginning to wonder if it was shipped or I would receive it. John 97084

- 48955

by: Roy M09/16/2014

The diodes are simple straightforward and easy to install. I needed six for a separate turn signal system so now I have two spares. They worked fine right out the gate. I won't be traveling for a while yet just getting ready. After I'm on the road a few months I'll report back if there is any issues. 151216

- 48955

by: Lin Owen09/16/2013

Order was pretty much as expected and the product was received in six days. I was given a way to track the shipment but when I tried to do it and clicked on track command the screen just sat there and stared at me. I finally called and got the info. Product is installed and performing as expected. 100070

- 48955

by: Jim11/18/2013

My husband ordered these but he doesn't do the computer thing so all I can say is he came in the house about 15 minutes after installing these and was very happy that it all went together so quickly and easily. And it all worked like it should when he finished. Husband happy=happy house! 107731

- 48955

by: Frank R03/24/2014

Good product that met my expectations. Easy to install and fairly intuitive. I was thinking about purchasing the high-power Roadmaster diodes (at twice the cost) but am glad I bought these--can't tell the difference in light output. Fast shipping from e-trailer. 121870

- 48955

by: John M09/04/2013

Not much to say about these except that they do exactly what they are supposed to do. They are a bit smaller than ones that I have used in the past which is nice for fitting in small spaces. It was an easy install on my 2006 Scion Xa 98215

- 48955

by: Glenn M09/06/2015

This product was easy to install. The system that was installed previously had the amber directional coming on when I hit the brakes. hooking up the diodes behind the tail lights is an easier system than the old one. It works great. 224255

- 48955

by: Glenn M09/06/2015

This product was easy to install. The system that was installed previously had the amber directional coming on when I hit the brakes. hooking up the diodes behind the tail lights is an easier system than the old one. It works great. 224254

- 48955

by: Rich M.03/25/2011

Great little item for towing as well as other little automotive & motorcycle projects. The etrailer team was fast to respond to my order and I had it within a couple of days. I plan to do more business with a company like this! 10339

- 48955

by: Mike R.09/14/2015

I am very pleased with the ease of wiring up my 2012 Jeep Compass with the Tail Light Isolating Diodes kit. Very simple procedure, once I watched the video. Took my time and completed the wiring in about 2 hours. 225490

- 48955

by: John H.07/22/2016

Works as any diode matrix should. In the past, I've used 2 amp silicon diodes, which works satisfactorily, but the tabs on the diodes make it so anyone should have no problems installing. 275189



John H - 07/22/2017

- 48955

by: Bryan L05/31/2015

Isolation diodes are hard to find in normal auto stores. RV retailer prices are out of sight. I am happy that etrailer could provide the product I needed at a very reasonable price 199330

- 48955

by: jerry L08/23/2015

The diode connectors arrived way quicker than I thought they would. Excellent service. Thank you Tori for expediting this order, it allowed me to keep my travel plans in the RV. 221231

- 48955

by: Thomas02/18/2013

This order I placed for the diode kits came in only 3 days in great shape and the right stuff! You can't ask for a better company to deal with! I will order from Etrailer again! 66770

- 48955

by: Bob H.10/24/2016

The diodes are great. They work as designed. As for dealing with etrailer - you can't find a better company to deal with. Don't hesitate to buy from 310267

- 48955

by: Don M09/21/2016

Product arrived on time and was easy to install. I already had the wiring run from the front of jeep to the tail lights, so adding the diodes only took 1 hour. 297072

- 48955

by: jim01/20/2017

I have ordered many times through and have never been disappointed. Great service and ever good products. I wish you were in my home town. 337004

- 48955

by: LEE W.09/20/2016


- 48955

by: Gene07/10/2017

Good price, reasonable shipping, arrived quickly, and work great. Only problem was that there were only 11 connectors in the package. 404071


I am sorry to hear about any inconvenience with your order, Gene, and have forwarded your review to customer service for direct follow-up with you.

-- Laura E - 07/15/2017

- 48955

by: Bob B.11/16/2014

I have had 2 orders with etrailer and both items were delivered very fast and of very good quality. I will order from them again. 161199

- 48955

by: tom nelson07/01/2014

good product!!!! don't like the krimpons,,, had to use my own..the diodes are working great!!!!! easy to put into the circuit !! 138556

- 48955

by: Paul05/03/2016

The diodes were exactly what I needed and easily installed in my tow vehicle. The price was a lot less than Roadmaster. 248265

- 48955

by: Lee07/12/2015

I haven't used the product yet, but they arrived in good shape and with fast shipping. I am extremely satisfied so far. 211175

- 48955

by: Art F05/02/2017

Always have parts in Stock, good prices and always there for you. Return to all the time. Thank you again! 376184


Thanks Art for the great review and rating!! Hopkins appreciates your business.

Hopkins C from - 05/11/2017

- 48955

by: David04/10/2011

Works the way it should. It controls the tail lights of the towed car. Glad there was also a video on installing it. 11451

- 48955

by: Stephen C05/09/2011

Quick ship, the diodes were exactly as depicted (and exactly what I was expecting). Good folks to do business with. 13114

- 48955

by: Rusty car07/06/2015

As I have not installed the item I am sure it will work as hoped . The appearance and product packaging was fine. 209770

- 48955

by: iggy05/19/2012

Best deal around when you need more than 4 isolating diodes. I used 7 with a spare backup. Can't beat the price 41021

- 48955

by: Tolby C07/23/2013

Very good product exactly as it was described was easy to install|||||||||||||||||||||||||||||||||| Thanks 91172

- 48955

by: Mike06/05/2017

Does what they say they do, no feedback to truck when toggling running lights on trailer via switch. 388964


Thanks Mike for the great review and rating!! Hopkins appreciates your business.

Hopkins C from - 06/06/2017

- 48955

by: Frank02/19/2014

Works as specified. Packaged as needed for standard project ( no extra unneeded stuff). 116932

- 48955

by: Guy L.05/12/2011

Excellent choice doing the job well. Quick and simple transaction shipped rapidly. 13687

- 48955

by: Wayne Petero06/05/2015

Great item, fast shipping, Good Communication, Would buy from again. A+++ ‹(•¿•)› 200815

- 48955

by: Steve L04/14/2016

Wiring isolation kit used on Smart car toad. Easy to install and worked great. 244345

- 48955

by: Kathleen D.08/03/2011

Needed in addition to std wiring kit for use on 5 wire system. Great value. KWD 20981

- 48955

by: Freddie01/27/2013

as always quick shipping,as advertised,good value & a great helpful staff. 64263

- 48955

by: Joe Stallings08/07/2015

Just what I needed. The speed of shipping and delivery was outstanding. 217632

- 48955

by: James02/28/2013

Product was as advertised. Delivery prompt. Quality as advertised. 68115

- 48955

by: LEE W.09/12/2016


- 48955

by: doug. s.01/04/2012

great product at a very good price. Very fast shipping. Thanks! 29071

- 48955

by: walt w.04/28/2017

reasonable shipping, fast service, have ordered multiful times 373609


Hello Walt, Thank you for purchasing our Diodes. We really appreciate your business and looking forward to doing more with you in the future.

Hopkins C from - 05/03/2017

- 48955

by: Gil J02/21/2012

Performs as expected. Great service, quick delivery! 32094

- 48955

by: George10/07/2011

suoer product and great help when i went to order 25231

- 48955

by: Ed H07/24/2012

did the job well. delivered on time great job. 49189

- 48955

by: Ronald02/02/2013

Arrived as promised, in good condition. 64843

- 48955

by: 4895505/17/2011

as discribed WORKS GREAT Thank you 14606

- 48955

by: Mark S.02/15/2016

works good and delivered as promised 237850

Show More Reviews

Ask the Experts about this Hopkins Accessories and Parts
Do you have a question about this Accessories and Part?

  • Parts Needed for Flat Towing a 2005 Mini Cooper 5 Speed Behind a Sprinter Class C Diesel Motorhome
  • Thanks for all of the information and research on parts for flat towing your 2005 Mini Cooper behind your Siesta Sprinter diesel Class C motor home. You have most of the parts correct, but there are some specific items you will need for your Mini. First, you need to wire the dinghy so that the combined brake and turn signals on the motor home will activate both the brake and turn signals on your Mini. The brake pedal would activate the brake lights with the key in the position you describe,...
    view full answer...

  • Availability of a Converter for US to European Wiring System
  • To convert from US to European wiring you will need the Vehicle to Vehicle Taillight Converter, item # 118158, which will convert the 2 wire system on a towing vehicle to a 3 wire system on a towed vehicle or trailer. You will run the taillight circuit normally and it is not required to run through the converter. If you are installing the converter on a towed vehicle you will need to use Tail Light Isolating Diodes, item # 48955, to keep the towing vehicle from back feeding into the...
    view full answer...

  • 2 Wire to 3 Wire Tow Vehicle Taillight Adapter for 2006 Chevrolet Colorado
  • You definitely can use the 4 diodes you purchased, # 48955, to wire your 2006 Chevrolet Colorado to be towed behind your Motorhome. Along with the connector you purchased and the diodes you will need an appropriate length of Bonded 4 Wire, # 16-4B-1. I would recommend about 30 feet. When wiring the taillights your brake and turn signal will use the same filament in the brake light bulb with a 4 diode kit. I have added a wiring diagram for you to make the process easier. To eliminate...
    view full answer...

  • How to Wire a 2007 Jeep Wrangler so All Running Lights Work Front and Back When Used as Toad
  • If you want to run the lights at the front of your toad you will need to install a diode at each running power wire going into the light bulb socket. You would need extra diodes, # 48955, and you would need to splice in extra wiring, # DW02360-1. Wiring the front running lights will be similar the wiring the rear running lights, see attached photo. You will need to make sure that your towing vehicles trailer wiring is capable of handling the extra amperage required by adding the...
    view full answer...

  • Wiring a RV to Tow a 1998 Saturn SL2
  • To wire your RV to tow your 1998 Saturn SL2 you will need part 38955. This kit will use the Saturn brake lights for both the brake lights and turn signals. If your SL2 has amber turn signals, you will also need part 118158, and two extra diodes, item # 48955, if you would like the amber turn signals to function.
    view full answer...

  • Diagram Showing How To Wire Taillight Diode Kit Like a 2-Wire System
  • The Hopkins # 48955 taillight diode kit can indeed be used to drive the running /brake lights on your Captiva like a three function lamp, without using the amber bulb for a turn signal. See the diagram I provided, and I'll also send you a copy as an email attachment.
    view full answer...

  • Do the Tail Light Isolating Diodes # 48955 Have to Be Installed at Rear of Vehicle
  • If you can find the taillight wiring for your vehicle under the hood of it then you would not have to install the diodes all the way at the rear of the vehicle. They would install the exact same under your hood as long as you can find the correct circuits.
    view full answer...

  • When Installing Tail Light Diode System, Does the Brake Fuse Need to be Pulled
  • Once the Tail Light Isolating Diode System is installed, no fuses need be removed. Think of the diodes as sort of a gatekeeper, that will allow the current to travel only from the tow vehicle to the tail lights of the vehicle being towed, without any worry of back feeding. For more details concerning the installation of Isolating Diodes, click on the provided links.
    view full answer...

  • Replacement 4-Pole Wiring Harness for 2005 GMC Yukon XL
  • You probably could rig your damaged wiring harness in the way you describe, using diodes to keep the circuits separated, but I suggest just replacing the harness with a 4-pole set-up like # 119147KIT. This is a hardwired harness with a substantial current capacity of 2.1 amps per stop/turn circuit and 7.5 amps for the tail lights. The risk in doing what you describe is that the wiring/circuits you would be accessing for signals may not be able to provide the required current for the...
    view full answer...

  • Diodes Only for Tow Bar Wiring for a 2012 Ford Fusion
  • We have diodes that you can purchase by themselves without the whole kit. Hopkins has a set of 4 diodes, # 48955, that you could use. Roadmaster also has a 4-pack, # RM-794. Or you can get a single diode using # RM-790, or a pair using # RM-792. It looks like your 2012 Ford Fusion would only need 4 diodes for tow bar wiring so one of the 4-packs is your best option if you need all of them.
    view full answer...

  • Wiring Needed for Towing a 2007 Kia Rio with a 2008 Freedom Express Class C RV
  • Your Kia requires a taillight converter, so you will need the Tail Light Isolating Diode System, part # 38955 and the Vehicle to Vehicle Taillight Converter, part # 118158 along with two extra diodes, which will require purchasing the Tail Light Isolating Diodes Qty 4, item # 48955, or the Roadmaster Hy-Power Diodes Qty 2, item # RM-792. If you do not mind the brake lights blinking when the turn signals are activated then you can just use the Tail Light Isolating Diode System, part #...
    view full answer...

  • Troubleshooting Wiring Harness Failure for 2004 Chevrolet Coloroado
  • Checking for shorts is a great first step in troubleshooting your lighting issues. As you mentioned, a regular wiring harness converter box has a max amperage of 2.1 amps per circuit for stop and turn lights, and a max amperage of 5 amps per circuit for the tail lights. The Tail Light Isolating Diodes # 48955 you mentioned have a max amperage of 3 amps. There are several other things to check that might be causing your problems. Checking these additional components will ensure that you...
    view full answer...

  • Towing a Motorcycle Trailer with 4-Way Square Connector with RAV4 with 4-Way Flat Connector
  • If you want to be able to tow the trailer with the RAV4 and with the motorcycle you are going to have to wire in a second connector on the trailer to match the 4-Way flat on the RAV4. The issue is that trailers designed to tow with motorcycles will likely have turn signals separate from the brake lights. The 4-Way flat on your RAV4 has combined turn signals and brake lights. This will require a special converter, # 118158, to maintain the separate circuits on the trailer. First,...
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  • Trailer Wiring Extension to Go From Motor Home to Flat Towed 2008 Mazda MX-5 Miata
  • What you need is the Roadmaster extension loop, # RM-300150-00. This is a 6 foot long cable with 4-Way ends. Both are male ends which is what you should need (the motor home and front of vehicle should have the same female connector). I have included a couple of helpful links to our FAQ articles on flat towing for you as well.
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  • How to Wire a 1996 Fiat Punto For Towing Behind a Motorhome
  • Wiring your fiat to be towed behind a RV will depend on the wiring system that is on the RV and on the Fiat. If the RV has a 4-Wire system and the Fiat has a 5-Wire system you will need the Tail Light Isolating Diode System, item # 38955. This kit will allow you to hook up the lights from the RV to the towed vehicle and will use the towed vehicles brake lights as turn signals also (see wiring diagram link). If you want to use the towed vehicles turn signal lamps also then you will need...
    view full answer...

  • Compatibility of Hopkins Tail Light Isolating Diodes # 48955 with 2009 Scion xB
  • You can use diodes like the # 48955. If you used the four diodes, you'd end up illuminating a single red bulb in your taillight assembly on each side, using a single bulb for running lights, turn signals and brake lights. Part # 38955 includes the same diodes, but provides a wiring harness. If you want to retain the operation of the separated tail lights of your xB, with the amber bulb for turn signals and the red bulbs for brake and running lamps, use the # 154-792-118158 kit. I've...
    view full answer...

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Info for this part was:

Photos by:
Theodore B

Expert Research:
Michael L

Video Edited:
Zack K

Expert Research:
Michael H

Expert Research:
Adam R

Updated by:
Laura H

Updated by:
Sarah W

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