Trailer brakes working intermittently

[Norrie46]

Our trailer brakes are not working all the time. We crossed Canada this Summer from West to East. When we started on Van Island I tried the brake module at the truck dashboard as it said no trailer attached. All the lights checked out ok just no brakes. Tried the plug in and out a few times but still the same. We left and tried it regularly on the road and sometimes it worked then stopped. Had the truck module checked in Canmore Alberta and they said it was ok. Eventually it got more reliable and was working when we drove through Ontario. Stayed in one place for five weeks then when we were hooking up again same problem occurred.
The annoying thing is the intermittent failures. We are leaving for Florida in November and I am thinking about dropping into Can Am in London Ont where we bought the trailer. Any suggestions would be welcome

Thanks

Norrie

[AlanMcD]

I don't have trailer brakes, either. The green slider light on the dashboard for the brake controller on my truck comes on intermittently but never long enough to be effective. Taking it to the dealer in a few weeks. Thing is I jumped the trailer connector pins and the trailer brake worked. Also had the truck dealer check the truck connector and it checks out ok so must be a trailer connector pin/wire issue is my guess. Or perhaps a intermittent connection between the two connector's pins.

-Alan
Cincinnati, OH

[Naper]

I had the same problem. Cleaned and tighten the connections put on a dab of dielectric grease. Problem solved.

[cwf]

Originally Posted by Naper

I had the same problem. Cleaned and tighten the connections put on a dab of dielectric grease. Problem solved.

Yup. What kind of truck?

First place to look as mentioned above, the umbilical electrical contacts. BE CAREFUL... you may have 12 volts present on at least one of the contacts... e careful cleaning the connections....clean ANY debris from the connectors. . reconnect several times. Does truck show "trailer connected"? Retry several (10 times) (this will give you several additional (connections) which will help improve the metal to metal contact. )

If this clears up the problem completely, coat the plugs metal connections with silicone dielectric..

Further checking.. (advisable for full system preflight/system check)


Disconnect umbilical.

Pull the emergency brake switch (engages emergency brakes). Presumably you have the disc brake system. If so you hear the brake servo run? If you don't have that style, go back to the wheels and listen for a "hum" signaling the brake magnets are active.

Next, do the mechanics of the brakes work?... With emergency brake engaged, have someone observe the trailer wheels as you try to move the trailer with the TV... do the brakes hold the trailer from moving? does one of the wheels brakes not engage?

On gravel, you can get idea how well your braking works by moving slowly while someone engages the emergency brake... tires should all LOCK simultaneously. This can be noted by a "skid" of the tires. I do this before a trip and then once a week. BUT.. I test immediately if I notice any braking change during operation..

Get this fixed.. it is a chance to learn more about YOUR RIG! Always time well spent.

[Royce]

I had that happen once. Traced the problem to the Brake light switch under the dash actuated by the brake pedal. A controller will not engage the brakes when you let off the gas but it will when you step on the brake pedal. It uses an accelerometer to decide how much to apply but it uses the brake light switch to decide to apply.

[romeb]

I have that problem fairly often too on both my Airstream and my enclosed cat trailer. I just pull over and push the plug in and out until it works. I've always assumed it was junk inside the exposed terminals on the trailer plug. There is a cover for the connector on the tow vehicle side so that's less likely. So when the trailer is parked I always hang the plug with the exposed terminals facing down so rain and other debris won't accumulate inside the plug. I've seen covers made for the plug but all the reviews said they contained the moisture and the covers did more harm than good.

[QC TORPEDO]

Had it happen after a brake repair. It was traced to a pinched wire. Check all connections at the brake assemblies on the axles. It could be bad wire and/or bad connections.

[xrvr]

Please be careful and don't tow without brakes. Go as soon as popular to an t.v. Or trailer repair shop. Towing without brakes irresponsible and dangerous. Good luck.

[Massey]

I had the same problem. Truck connector was good, wire whip from truck to trailer was good, I found the issue in the connector on the trailer. Connections were loose. Tried to tighten but ended up replaced the connector on the trailer, because the original was dry rot and needed to be replaced Wires were short which made it a bit more challenging. If you attempt the work, take a picture before disconnecting anything to have reference. If possible move one wire at a time to new connector

[Norrie46]

Thanks to all for your very useful replies
Norrie