Trailer Brakes Lock Up When Hooked to Breakaway Battery

Question

Question:

Hi John, thank you for the wiring info. It is factory wired & I made sure to rewired it exactly like the original. It was also the identical mfg & model as the original breakaway switch. I did notice that the original switch was fastened securely unlike the instructions on the new one which stated: to allow for it to pivot, unlike the factory fastened installation. Should the breakaway switch mounting plate be secure? Or even without a firm connection to the battery could I have melted a wire or possibly a fuse somewhere along the its length? Could the switch be defective? There is a fare sized box just under the front of the rig that all the wires go into, should I inspect it? It is a 2005 Fleetwood Pegasus, Vin #1500319. Thanks for your help!

asked by: Tom

1

Helpful Expert Reply:

It sounds like you found out why the brakes were activated while you were towing the trailer to storage, so that solves that problem. Now we will want to figure out why the brakes are still locking up with the new breakaway switch. Even if you fried the brake magnets, the brakes should not lock up if the breakaway system is setup properly. I recommend inspecting the wiring of the breakaway system on your trailer to see why power is reaching the brake assemblies. I have attached a wiring diagram that shows how the breakaway system should be installed.

Without being able to see the trailer it is difficult to tell you what the issue is exactly, but there are a few things you can look for. Once you have the breakaway system set up properly. Look for any damaged sections of wire. It may be possible that some wires are crossed or connected to the wrong circuit. Your electric brake wire should run from your trailer connector directly back to your trailer brakes and only one wire from the breakaway switch should be spliced in. There should be no other wires spliced in to the electric brake power wire other than the breakaway switch and brake magnets.

Once you have the wiring completed, you may want to replace your brake assemblies. I also recommend looking at the hub surface and bearings. If the hub became hot, there is a chance that the bearings and grease seal could have been affected. If you would like new parts, I would just need a little more information about your trailer to get you the correct parts. If you can tell me the VIN of your trailer, I can give you all of the correct replacement parts you need for your brakes and hubs. The VIN can be located on the specs plate that is typically located on the tongue of the trailer.

expert reply by: John H

1

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Tom

6/13/2014

Hi John, thank you for the wiring info. It is factory wired & I made sure to rewired it exactly like the original. It was also the identical mfg & model as the original breakaway switch. I did notice that the original switch was fastened securely unlike the instructions on the new one which stated: to allow for it to pivot, unlike the factory fastened installation. Should the breakaway switch mounting plate be secure? Or even without a firm connection to the battery could I have melted a wire or possibly a fuse somewhere along the its length? Could the switch be defective? There is a fare sized box just under the front of the rig that all the wires go into, should I inspect it? It is a 2005 Fleetwood Pegasus, Vin #1500319. Thanks for your help!

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John H.

6/13/2014

The breakaway switch should be mounted securely on your trailer. It does not matter if it is completely tight or if there is a little room for it to move, you just want to make sure it will not fall off or vibrate loose. There could be the possibility of a melted wire, but a blown fuse in unlikely. There should be no fuses on the electric brake circuit on the trailer. I would suspect a loose or damaged wire somewhere between the trailer connector and brake magnets. The switch could be defective as well. You can test that using a circuit tester like part # PTW2993. Probe the wire going from the breakaway switch to the electric brake circuit. If you have power on that wire with the breakaway pin in place, then the switch is bad. I probably wouldn't be a bad idea to inspect the junction box to make sure some wires or terminals are not touching. Thank you for sending the VIN for your trailer. If you inspect your brakes and hubs and determine that you need new parts, I have a few options that should work for you. According to Fleetwood, your trailer came with an axle built by Quality Axles. Unfortunately this company has been bought and sold since your trailer was purchased, so I do not have specific hub and brake part information, but I have the bearings and grease seal information that will allow us to choose new parts. According to Fleetwood, your trailer has a 3,500 lb axle that is compatible with Dexter brakes and drums. For brakes, I recommend the etrailer.com Self Adjusting Electric Brake Assemblies, # AKEBRK-35R-SA for right hand and # AKEBRK-35L-SA for left hand. I recommend replacing the entire brake assemblies so you get all new parts. If you have to replace multiple parts, it is usually more cost effective to replace the entire brake assemblies. Before purchasing a hub/drum assembly, you will want to check the bolt pattern on your current hubs. Fleetwood could not tell me the bolt pattern used on those hubs and wheels. I have attached a help article on how to determine your bolt pattern if you do not know what it is. If your hubs have a 5 on 4-1/2 inch bolt pattern, then I recommend the Dexter Hub/Drum Assembly, # AKHD-545-35-K. If you have a 5 on 5 bolt pattern, then use part # AKHD-550-35-K. If you have a different bolt pattern, let me know.

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