Trailer wiring and surge brakes

[KM2]

I'm stumped. I get me boat out this spring and after looking things over notice my trailers disk brakes are a little rusty. This shouldn't be I just drove over a 100 miles and if the brakes were working the rust would be gone. After much trial and error I realized if the trailer wiring was unpluged the brakes worked great. So well in fact that I'm shocked I may have towed all last summer with out working trailer brakes. FYI My boats loaded is around 3500# and my tow vehicle is a ford expedition. I checked the wiring which I did myself last year and things match up. I mean the colors match on the wiring to the round plug in. My guess is the back up solonoid is locking out all of the time. Any guesses to why?<br />Is it a fuse, the back up solonoid or wiring?? Any ideas would be appreciate? Any info on how the back up/lock out works would be helpful. Thanks

 

[fsherrerd]

Re: Trailer wiring and surge brakes

The electronic solenoid on your brake actuator is there to keep pressure off your disc brakes when backing up. Most brake actuators made for disc brakes circulate the fluid back into the master cylinder. Simply, when you begin to back up, the by-pass solenoid (which needs to be wired into your backup light circuit) energizes and diverts the pressure back into the master cylinder instead of to the brake assemblies.<br /><br />You should begin by making sure the solenoid is wired to the backup light circuit. To do this, after setting the tow vehicle parking brake, use a second person to put the tow vehicle in reverse and using a test light check for power at the solenoid and feel for it to activate. If your test light shows power and you don't feel the valve activate, probably a bad valve. If you get no power re-check your wiring. <br /><br />As a second trobleshooting item, try turning on you lights and testing for power and lastly try your brakes lights and test. Obviously if you get power or activation from one of these circuits you have a wiring problem for sure.

 

[Solittle]

Re: Trailer wiring and surge brakes

An even easier way to test the solinoid is to attach the tow vehicle to the trailer without connecting the solinoid and try to backup. If your trailer won't move connect it and try backing up again. You should be able to backup only when it is connected.<br /><br />Tip - carry an extra electrical plug for a vehicle if you should ever need a friend to move your trailer and can't use your tow vehicle.<br /><br />I have had my disks for about 5 yrs and think they are great - - a must for a boat of any size especially if dunked in salt water.

 

[KM2]

Re: Trailer wiring and surge brakes

Thanks Guys, <br /><br />I worked on it over the weekend. The wiring is working and correct. Got a $3 tester and made sure. Found I had one of my tail light bulbs out and replaced the light assembly too. The solenoid is making a clicking noise when powered. I backed up with wiring unplugged and the brakes stopped me right away.....<br />I'm not feeling the brakes as I go down the road. A few more trial runs down the street with the brakes on and then disconnected should let me if they are working. Thanks again for the suggestions. Kevin

 

[MIKE F]

Re: Trailer wiring and surge brakes

I just added wires for the solenoid lockout and a ground wire to go along with it (so I can unplug my regular harness while dunking) on a brand new truck. I plugged everything in and got nothing. No lights working on the trailer, but I was getting a clicking from the solenoid. It turns out that the ground connection on my trailer decided to crap out. I could move the ground wire and all lights worked properly and the solenoid stoppped clicking. I just put a new connection on the ground and all is okay now.