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Pollak Circuit Breaker - Cycling/Automatic Reset - 40 Amp - Straight Mount Bracket

Pollak Circuit Breaker - Cycling/Automatic Reset - 40 Amp - Straight Mount Bracket

Item # PK54540
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Pollak Wiring - PK54540
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This single-pole, thermal circuit breaker features a continuous cycle with an automatic reset. Breaker prevents battery from draining and auxiliary application from overdrawing. Typically used on hot leads. 1-800-940-8924 to order Pollak accessories and parts part number PK54540 or order online at Free expert support on all Pollak products. Guaranteed Lowest Price and Fastest Shipping for Pollak Circuit Breaker - Cycling/Automatic Reset - 40 Amp - Straight Mount Bracket. Accessories and Parts reviews from real customers.
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  • Reviews (38)
  • Q & A (0)
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Pollak Accessories and Parts - PK54540

  • Wiring
  • Circuit Breaker
  • Pollak
  • 40 Amp

This single-pole, thermal circuit breaker features a continuous cycle with an automatic reset. Breaker prevents battery from draining and auxiliary application from overdrawing. Typically used on hot leads.


  • Metal housing with straight mounting bracket
    • 2-Piece design
    • Attached by spot welding
  • Cycling automatic reset
    • Cycles continuously during over-current condition
    • Returns to run mode when source of over-current is removed
  • (2) 10-32 Studs
    • Yellow, dichromate (copper color) plating on battery terminal
    • Zinc plating (silver color) on auxiliary terminal
  • Straight mounting bracket
  • SAE Standard J553 compliant


  • Applications: Accessory circuit, cooling fan, door locks, headlamps, tail lamps, window lift, sunroof, trailering package, electric brake controls
  • Terminal dimensions: 0.66" long
  • Current rating: 40 DC amp
  • Voltage rating: 12 VDC (Voltage Direct Current)
  • Operating temperature: -10 degrees F (-23 degrees C) to 150 degrees F (65 degrees C)
  • Storage temperature: -20 degrees F (-29 degrees C) to 200 degrees F (93 degrees C)
  • 1-Year limited warranty

54-540 Pollak Single-Way, Thermal Circuit Breaker - Cycling/Automatic Reset - Straight Mounting Bracket - 40 Amp

Alternate to 9510

Customer Reviews

Pollak Circuit Breaker - Cycling/Automatic Reset - 40 Amp - Straight Mount Bracket - PK54540

Average Customer Rating:  4.9 out of 5 stars   (38 Customer Reviews)

This single-pole, thermal circuit breaker features a continuous cycle with an automatic reset. Breaker prevents battery from draining and auxiliary application from overdrawing. Typically used on hot leads.

by: has been an easy company to work with. They were helpful in making sure we had what we needed to install our trailer hitch successfully. Thank you for your help. We have recommended you to friends and family and will continue to do business with you in the future.

Still a great product and a great company!
Debbie H - 05/13/2021


Works perfectly… No problems…


All things listed were required although the terminals did not have a large enough opening as I needed. Also, it said that I needed 10 gauge wire but my Chevrolet is wired with 14 gauge so I have to modify the wiring. The idea was to hot wire the 12v pin on my stock 7 pin connector to supply my trailer with the necessary 12v to charge the trailer battery when on the road. However, after checking the stock wiring, I found it to be in good condition so I was able to reuse the existing stock wiring which was still in the stock wiring harness to the 7 pin hitch at the rear of my vehicle. I was able to pull the existing 12v wire off of the 12v pin in the fuse box and attach it to the new Pollack circuit breaker I purchased from I then only needed to use about 1 foot of the 10 gauge wire to go from my battery to the other pole of the Pollack circuit breaker. Very simple procedure sine I didn't have to run the 10 gauge back to the rear of the vehicle and attach it to the existing 14 gauge wire I had. The third picture I've posted with the red and blue wires next to each other show you the 10 gauge blue wire I purchased and the 14 gauge stock red wire that was in my truck.


Perfect addition to protect my Tekonsha RF Prodigy wireless trailer brake controller. Simple to install and excellent protection.


Thanks for the detailed help with the wiring harness and wiring tips for my Nissan Pathfinder. This made the installation a breeze.


connectors and breakers to hook up my brake controller arrived in order, installed easily, and lasted 1 year so far...


Lots of purchases from etrailer. They have the parts I need at the best prices. And the technical info I need to get the job done.

A year later and all my etrailer products still working.
Lee - 09/21/2018


Made my connection to a F150 for the brake controller very easy. The staff at Etrailer is to be commended as to how helpful they were with my hookup, on a Sunday no less. Outstanding customer support. Thank you!


Great service as always!! Fast delivery! Etrailer has it all covered with product and install information, they make it easy!!


Works as designed. Another great product from etrailer

Product works as designed. Havent had any issues with it at all.
Neal B - 11/04/2017


The customer service I received was second to none. William was very knowledgeable in ever aspect of my purchase. Hitch is of high quality and good appearance. Will definitely buy their again.


Easy installation. Super easy to use.


Works good with my application.

Working great
James C - 01/05/2018


Used this in a circuit to wire in my truck to charge my travel trailer battery while driving on the road. Works great.


Great product, exact replacement in my loader. Hard to get the old one out.


Install couldn't be easier. Delivery was fast. Video showed everything I needed to know.
Thanks etrailer


Very good quality


I have not performed my installation yet but this is to compliment you on your order processing and shipping. This is my second order and everything was well packaged and delivered right on time. I recommend your site to people all the time. Thanks!


Item was purchased to replace circuit breaker on a backhoe. It was cheaper then backhoe dealer,seems to be the same thing. I will try it,hope it works like I think it will.


I rated the product in the middle category because until the charging system fails, I will not know how well this device works.


Quick install and well marked for proper attachment.


Does what is designed to do.

Still working just as its supposed to.
Clint M - 05/03/2018


Just what we wanted for rebuild. Looks great, good function


Job done right!

Perfect... reliable...
Karl W - 05/28/2017


Easily mounted, tripped a couple times and reset as designed

Show More Reviews

Ask the Experts about this Pollak Accessories and Parts

  • Wiring Diagram for 7-Way on a 2008 Chevy Silverado
    Yes, we have diagrams for nearly every type of trailer wiring connector available. Check out the link I attached to see them all. Most likely you have a 7-way on your 2008 Chevy Silverado so I attached a picture of a diagram of a 7-way.
    view full answer...
    Image 1 for
  • Recommended Replacement Circuit Breaker for 2012 Forest River Grey Wolf
    The bad circuit breaker on your trailer should have an amperage rating indicated on it to let you choose the correct replacement. That current rating will appear as "20A" for a 20-amp breaker, etc. The linked page will show you all breakers we offer which range from 20 to 150 amp values. If you need, for example, an automatically resetting breaker in a 40-amp value, you can use # PK54540.
    view full answer...
  • Trouble Shooting AC And Circuit Breaker Function
    The Pollak Circuit Breaker - Cycling/Automatic Reset - 40 Amp # PK54540 is a continuously cycling circuit that will reset itself. The Copper terminal goes to battery and the zinc terminal to accessory. To run a 30 Amp system, you will need a larger circuit breaker or it would trip the breaker each time it started up. A bad circuit breaker may be the issue, but typically an AC unit cannot run off a 12V battery because it simple pulls too much power too quickly. A deep cycle battery may...
    view full answer...
  • How to Get Power to the 7-Way connector on a 2003 Chevrolet Tahoe to Power Interior Trailer Lights
    It sounds like your power wire under the hood is not connected to the power distribution box stud that is under the hood of the vehicle. The power wire is located on the side of the power distribution box closest to the firewall and is underneath a bracket. Two covers will need to be removed and you will see the wire with a ring terminal on it that needs to be connected to the power stud farthest from the cab. A 40 amp fuse will need to be placed in the last spot closest to the stud. The...
    view full answer...
  • How to Charge Trailer Battery with 7-Way Connector
    The 12 Volt accessory lead on the 6 or 7-way connector can be used to keep the battery on your trailer charged. Run the accessory lead from the trailer connector to the positive battery terminal on the trailer battery, and ground the negative terminal to the trailer frame. Please read and follow all of the battery manufacturers guidelines regarding battery charging. The 12 volt pin of the 7-way is the 1:00 position.
    view full answer...
  • Should 12 Volt Circuit be the Center Pin or 1 Oclock Pin in a Vehicle Side 7-Way Trailer Connector
    I would stick with the standard 12 volt circuit at the 1:00 position rather than use the center pin, which is normally used for reverse lights. Please note that the 12 volt circuit on a trailer connector, no matter which pin it is associated with, will not be able to charge up a 12 volt vehicle battery (if that was your plan). It can only maintain the charge level of the battery. So if you had something using power from the Toad battery while flat towing it then the drain would be greater...
    view full answer...
  • How Would a Brake Controller Install in a Motorhome
    To install a brake controller in a motorhome is just like installing a brake controller in a vehicle. If you were to install the Tekonsha P3 # 90195 you basically need to just make 4 connections. The black wire of the P3 will need to be run to the positive side of the motorhome battery through a circuit breaker like part # PK54540. The white wire will need to be grounded to the negative side of the battery. The red wire will be run to the stoplight switch wire. This wire is typically...
    view full answer...
  • Availability of Adapter For Connecting 6-Way Round on Trailer to 4-Way Flat on Tow Vehicle
    I would recommend to use the Tow Ready 4-Way to 6-Way Adapter, part # 30637. If you only want to use the basic lighting functions provided by the 4-Way (left/right turn, brake, and running lights) then all you will need to do is plug the 4-Way end of the # 30637 adapter, into the vehicle 4-Way. The trailer 6-Way will then plug into the 6-Way receptacle on the adapter. You will also need to ground the white wire on the adapter to the vehicle frame at a clean and corrosion free metal surface....
    view full answer...
  • Will the 4-Way to 6 Pole Adapter # 37175 Fit a 2000 Ford F-150 with Factory 4-Way
    The protective cover on the Adapter, # 37175 should not interfere with the standard 4-Way on your 2000 Ford F-150. It may be snug at first but you do want a tight connection. I have included a link to a video review of this harness for you. In order to make the 6 pole fully functional, you will need to hardwire in the remaining wires on the adapter. You must ground the white wire to the vehicle frame using the white wire on the adapter. The blue wire will connect to a brake controller....
    view full answer...
  • Recommendations for Charging and Maintaining a Trailer Battery 2012 Hyundai Santa Fe
    You will want to run the the wire through a 40 amp circuit breaker like our part # PK54540 from the black wire of the Tow Ready Adapter # 30717 to the positive side of your vehicle battery. You should note that this will help keep a trailer battery from losing its charge, but it would not charge a dead battery. The best way to prevent excessive vehicle battery drain would be to disconnect the trailer wiring whenever you park. Or you could use a Tow Ready Battery Isolation Solenoid # TR118665....
    view full answer...
  • Adapter to Connect 4-Way on Vehicle to 6-Way Round on Trailer
    A vehicle end wiring harness using a 4-Way Flat connector should have 3 female plugs and 1 male pin. A matching 4-Way Flat trailer connector would have 3 male pins and 1 female plug like on the Tow Ready Adapter 4-Way Flat to 6-Way Round, part # 30637. The # 30637 adapter is designed to plug into a 4-Way Flat on a vehicle and the 6-Way Round on the other end, with the male pins, will plug into a 6-Way Round on the trailer that has 6 female plugs. I am including a link to a FAQ page on...
    view full answer...
  • Hardwiring in Brake Controller to 2007 Dodge Ram 1500 with Factory 4-Way and Active Port Under Dash
    A couple of things: We recommend a 40 amp circuit breaker on the 12 volt circuit to the 7-Way. This is because you never know what you might tow! For a 40 amp circuit breaker you can use # PK54540. The wire match ups you provided are correct. The only issue is if the harness under the dash is actually fully active. It is possible that it is but it also might not be. The only way to know other than testing with a circuit tester is to try it. though it sounds like you tested and it is working. That...
    view full answer...
  • Prodigy P3 Brake Controller 90195 Installation in 2005 Ford F-150
    On your Ford truck the light green wire does carry the brake switch signal and this one wire only should connect to the RED input wire on the controller. The three other wires to your P3 brake controller, white, blue and black, attach to the vehicle as follows. The white wire is ground and attaches to the battery negative terminal; the blue wire is the controller's brake output signal to the 7-way; and the black wire connects to the battery positive terminal through a 30- or 40-amp circuit...
    view full answer...
  • Lost Wiring Diagram for Wiring a 4-Way to 7-Way Trailer Connector on Vehicle
    Yes, the black wire goes to the number 4 terminal which is in the eleven o-clock position inside the 7-Way connector and is the 12 volt power lead. This wire should be wired to the positive battery terminal through a 40 amp Circuit Breaker, item # PK54540. The yellow wire goes to the number 7 terminal in the center of the 7-Way and is for auxillary power, or can be used for reverse lights. This wire will need to be wired accordingly. Use 10 gauge wire for these circuits.
    view full answer...
  • Installing a Brake Controller on a 1999 GMC Yukon Old Body Style with Towing Package
    There is not a connector available under the hood of your vehicle to connect a brake controller to. The easiest way to install a brake controller is to use a Universal Brake Control Wiring Kit, item # 5506, which includes the wire, breaker and connectors to install an electric brake controller. The original wiring that is ran on your vehicle is very hard to access and it is much easier to run the wires on this vehicle yourself. If you need to run a power wire to the trailer connector you...
    view full answer...
  • Voyager Trailer Brake Controller 39510 Wiring Installation in 2002 Toyota Tundra
    Yes, on trailer brake controller installation the red input-signal wire will connect to the COLD side of the brake light switch; this is the pole that goes hot only when you press the pedal and at no other time. The other three wires on a brake controller are 12V operating power (black wire) that connects to the battery + terminal through a 40-amp breaker like # PK54540; the ground (white wire) that connects to the battery negative terminal; and the blue output wire that gets routed to...
    view full answer...
  • What are the Wire Function on the Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector 30717
    On a 4 to 7-Way adapter like # 30717 you will have to make sure the yellow wire is connected to a reverse light circuit. You can tap into a reverse light circuit at the back of a reverse light. On a trailer with hydraulic brakes and an electric reverse lockout, it is the reverse light circuit on the vehicle that operates the solenoid to allow you to back the trailer up without the brakes engaging. The white wire on the harness gets grounded to the vehicle frame. Black is for 12 volt power...
    view full answer...
  • What is the Purpose of the Black Wire Between the 7-Way and Battery
    The 40 amp circuit breaker part # PK54540 gets installed on the 12 volt power wire between the 7-way trailer connector and the vehicle's battery. The purpose of this wire is to provide a charge for an auxiliary or breakaway battery on the trailer. It will go to the 1 o'clock pin on the 7-way which you can see from the attached photo. It is not required nor needed for the 7-way to function if that is what you are after.
    view full answer...
    Image 1 for Image 2 for
  • Current Output Capacity for Tekonsha 4-Pole Trailer Wiring Harness 118675
    4-pole wiring harnesses, which carry stop, turn and tail light signals, generally have a current output in the range of 2 to 4 amps in each of the stop/turn circuits and from 4 to 7.5-amps in the taillight circuit. These current ratings can vary by harness manufacturer and by vehicle year, make and model. The Tekonsha harness # 118675 which fits your 2016 VW Tiguan has a maximum output of 4.2- and 7.5-amps. On a 7-way RV-style trailer connector the 12V auxiliary power circuit will usually...
    view full answer...
  • Adding an In Line Fuse to a 12 V Power Lead from a Vehicle Battery to a Trailer Connector
    I assume you are wanting to add an in line fuse to a 12V power circuit running from your vehicle battery to the trailer connector on your vehicle. There are a few things to consider before adding an in line fuse to a 12V power lead to a trailer connector. If your vehicle currently has a factory installed 7-way trailer connector, then the power lead will already have a fuse. If you are adding a 12V power lead to your vehicle, then we typically require a 40 amp circuit breaker, like part...
    view full answer...
  • Completing the Wiring for a 7-Way Trailer Connector
    The black wire coming out of the 7-way connector should be connected to 12 volt power from the vehicle battery. The blue wire connects to the trailer brake feed circuit coming from the brake controller mounted in the vehicle. If you need to run these wires for your connector you will need a 40 amp circuit breaker, item # PK54540, to attach the black power wire to the positive battery terminal. You can use the Wiring Kit for Electric Brake Controllers, item # 5506 and the 40 amp circuit...
    view full answer...
  • How to Tell Which Terminal is for the Battery on a Pollak In Line Circuit Breaker # PK54520
    Since your circuit breaker does not have different color terminals you will want to look closely on the Pollak 20 Amp Circuit Breaker, part # PK54520, and the Pollak 40 Amp Circuit Breaker, part # PK54540 for markings. The poles will be marked with BAT right next to the battery terminal and AUX right next to the auxiliary terminal. A circuit breaker should have one of the poles marked as a battery terminal.
    view full answer...
  • How to Determine Circuit Breaker Amp Rating for a 2018 Venture Sonic 200VML
    I can help you figure out what your circuit breakers are rated for but unfortunately I don't know what circuit breakers came on your 2018 Venture Sonic 200VML. I can say that we typically recommend using either a 20A or 30A circuit breaker for the 12V power so if your manual says 30A then I would tend to lean that way. You can be 100% certain by disconnecting all of your wiring and removing those covers on the circuit breakers you should then be able to tell the rating as the circuit breakers...
    view full answer...
    Image 1 for Image 2 for
  • 4-Way to 7-Way Vehicle End Trailer Wiring Connector Color Code
    The pins on the Adapter 4 Pole to 7 Pole Vehicle End, item # 30717, and the pins on the trailer connector should be wired the same. If you are just wondering what to connect the loose wires from the adapter to, they are, White is the ground, Black is connected to the battery of your vehicle through a 40 amp circuit breaker, item # PK54540, Blue is connected to the blue wire on the brake controller and Yellow is the the optional auxiliary function or it can be connected to the reverse...
    view full answer...
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Info for this part was:

Employee Mike L
Expert Research:
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Expert Research:
Jameson C
Employee Adam R
Expert Research:
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Employee Tyler C
Written by:
Tyler C
Employee Joshua S
Video Edited:
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