No brakes - electrical?

[cbenslay]

I just took my travel trailer out for the first time this year. It's a Coachman Catalina 19RD. Unfortunately, during my routine check I determined that my trailer brakes weren't working.

I did make the mistake of towing it home from storage without a battery in it. I found out it wouldn't have brakes then. Chalk that up to experience - don't do that again.

Unfortunately even after putting the fully charged battery in the trailer I still did not have brakes. I even pulled the break-away out and still no brakes. I am assuming it has to be electrical. I found it very unlikely that all 4 calipers are "stuck".


I traced the wires and did not see anything obvious. I checked all of the fuses inside the trailer and they were all OK. I did not see any fuses under the trailer. I did find one junction box up by the tongue. I had power going to one wire from the break-away switch, but not the other one. I would think that when the break-away is activated I would have had power to both wires. I did not check the wires before the break-away was pulled my my wife - I was under the trailer.

Any ideas?!

Thanks,

[OldCoot]

Would guess the plug in receptacle terminals are corroded or bent. Also check the plug wiring on the back.

[cbenslay]

Where are the plug-in receptacles terminals you are referring to?

Thanks,
Chuck

Originally Posted by OldCoot

Would guess the plug in receptacle terminals are corroded or bent. Also check the plug wiring on the back.

[dkwin1]

The plug coming from the trailer and the receptacle coming from your car. Make sure both are clean (it is VERY COMMON) for these to get corroded over the winter months and cause a "no connection" between the 2. Clean both those and try again. Good luck

[OldCoot]

The ones inside the receptacle that are visible when you lift the little door and also on the end of the trailer pigtail. The big round plug. Also check the terminals on the back of the truck receptacle as a wire may have come loose. Do you have lights, etc. when plugged into the truck?

[cbenslay]

I have a connection to the trailer brake controller (red light is on) and all of my lights etc are working fine. I will double check them though.

Right now it is sitting in my driveway (off of the truck), if I pull the break away shouldn't the brakes be applied as long as there is a battery in it? They aren't...

Thanks again,
Chuck

[OldCoot]

Check voltage at brake terminal in receptacle. If you have power there with the brake pedal pushed, you have a break in the brake wire in the pigtail or on the trailer itself. Should be a box where the pigtail ties to the trailer, inspect in there too.

[ChooChooMan74]

When you pull the breakaway, are you trying to drag it? If not, do you have a compass? Holding it near the drums will cause the needle to move when the brakes are activated.

Your brakes shoes may just be severely out of adjustment, also.

Also, the brakes will work without a battery in the trailer, but the breakaway is inoperable.

[cbenslay]

Will do. Thanks!

Originally Posted by OldCoot

Check voltage at brake terminal in receptacle. If you have power there with the brake pedal pushed, you have a break in the brake wire in the pigtail or on the trailer itself. Should be a box where the pigtail ties to the trailer, inspect in there too.

[cbenslay]

When I first realized there was a problem I was trying to drag it. There was no resistance at all. Thanks for the tip about the compass. I was just testing for current after the break-away was pulled. I am going to pull the tires and physically check the brakes tomorrow if I need to. They seemed OK when I parked it in storage last fall though...

Thanks,
Chuck

Originally Posted by ChooChooMan74

When you pull the breakaway, are you trying to drag it? If not, do you have a compass? Holding it near the drums will cause the needle to move when the brakes are activated.

Your brakes shoes may just be severely out of adjustment, also.

Also, the brakes will work without a battery in the trailer, but the breakaway is inoperable.

[cbenslay]

Thanks for all of the assistance. I finally had time (and help) to climb under the trailer while getting brakes pressed etc. Now, I am more confused about some things and knowledgeable about others...

Here is what I found:

When the truck is not running I have these voltages at the plug at the rear of the truck:
2 Blue 4.52 - trailer brake
3 Brown 11.73 - running lights
4 Black 11.73 - 12v power
5 Yellow .07 - Lt turn & brake
6 Green .07 - Rt turn & brake
7 Purple .01 - Back up lights

Then I attached the plug from my trailer and engaged the "emergency" stop button on the brake controller. I climbed under the trailer and opened the junction and tested the wires from there. Here is what I got:

2 Blue 0.00 - Brake controller (NOT GOOD)
3 Brown 0.22 - running lights (they were all on though)
4 Black 13.38
5 Yellow 0.01 - nothing connected to it from the trailer
6 Green 12.96

After I saw that #2 was at 0.00, I re-tested the voltage at the receptacle at the back of my truck with the "emergency" button depressed on the brake controller. It read the same as before, 4.5... I don't know if the brake controller functions when the plug is disconnected though. I know the "connection" light on the controller goes out so it probably doesn't have any effect without the plug inserted.

I am a litle concerned about the truck wiring because I remembered that a chipmunk had chewed a lot of wires in my fuse box last summer. A mechanic fixed everything and I haven't had any problems. I can't remember if we pulled the trailer since then or not. Maybe something got missed...

Hopefully, someone can make sense of my numbers and give me some ideas. I find it hard to believe that only the blue wire in that big package of wires is bad. Maybe it is though...

I also determined my "break-away" switch is junk! The contacts were bad before. I cleaned them up and got it working. Then I replaced the plastic plug. When I tested voltages later the plastic plug would NOT come out. It broke and now I have to replace the switch....

Thanks for any help!

[cbenslay]

Any ideas?

I am wondering if the voltage on the #2 wire at the back of the truck should change when the button is pressed on the brake controller. I have an "emergency" button that you can depress to help if the trailer begins to sway. The voltage never moves from about 4.3 volts...

I really need to determine if it is the trucks wiring or my trailers. I am leaning toward the truck now.

Thanks,
Chuck

[cbenslay]

I have a mechanic that is going to look at the wiring issues from the Chipmunk. However, he is unfamiliar with brake controllers and their output to the trailer connection.

Does anyone know if the voltage on the #2 wire should change when the brake controller is in use?

Thanks yet again
Chuck