Intermittent Brakes on '71 Tradewind

[1hank1]

Not sure what's going on here, but on my 1971 Tradewind I'm having an intermittent braking problem. The umbilical very well could be the problem, either in one of the two connectors or maybe even a wire, but I'd like to re-do the entire system for safe measure.

When I noticed the problem it was raining very hard outside. So my first question is, is there a known problem with this model where rain/water affects braking?

At the same time I lost brakes, the left rear taillight also quit working. Neither the running light nor the signal light was working. The right rear does not work anyway (rusty) so I do not know if both rear taillights quit at the same time. All the other running lights were working fine. Could the two problems be related?

I removed the cover from inside the trailer to ome the connections on the 7-pin connector. While doing so I heard something that sounded like a pump running when the brake pedal was applied. As soon as I heard this "hummm" I test drove the trailer and the brakes were working fine again, and so was the taillight. What is this "hummmm" and where is it coming from?

Is there a wiring diagram available online detailing the braking system of my trailer?

And lastly, I would like to replace all the rusty components of my tail light assemblies. Is there a "kit" to do such a thing?

[overlander64]

Greetings 1hank1!

Originally Posted by 1hank1

Not sure what's going on here, but on my 1971 Tradewind I'm having an intermittent braking problem. The umbilical very well could be the problem, either in one of the two connectors or maybe even a wire, but I'd like to re-do the entire system for safe measure.

Most well-stocked RV Dealers will have bulk 7-conductor umbilical cord wire that they sell by the foot, and this makes a good point to begin replacement of the umbilical cord. With the cord/cable in-hand, the decision of connector type then presents itself. Generally the consensus is the current "industry standard" seven blade connector. I went with this for a number of years but found that corrosion generally meant replacing the connector on the tow vehicle annually and on the trailer every third year. Several years ago, I switchd to the seven-pin round heavy duty connector typically used in over-the-road trucks . . . these connectors are all metal and I have yet to encounter a corrosion problem with either end. You may find that you also need a new set of connectors for the trailer side if you coach is among the 1970s models that had a removable umbilical cord that plugs into the front of the coach.

Originally Posted by 1hank1

When I noticed the problem it was raining very hard outside. So my first question is, is there a known problem with this model where rain/water affects braking?

There isn't one common problem in this regard, but any corroded connection, loose ground, or dirty connection is going to be negatively impacted when moisture is introduced. With some brake controllers it may be necessary to adjust gain or leading when in heavy rain but that is more to reduce the potential of skidding than loss of braking. I would suspect corrosion or ground issues on the circuits involved.

Originally Posted by 1hank1

At the same time I lost brakes, the left rear taillight also quit working. Neither the running light nor the signal light was working. The right rear does not work anyway (rusty) so I do not know if both rear taillights quit at the same time. All the other running lights were working fine. Could the two problems be related?

I suspect that there are either direct relationships or parallels between and among the problems. Dirt and corrosion are the culprits of many problems in the 12-volt system as it the lack of adequate grounding.

Originally Posted by 1hank1

I removed the cover from inside the trailer to ome the connections on the 7-pin connector. While doing so I heard something that sounded like a pump running when the brake pedal was applied. As soon as I heard this "hummm" I test drove the trailer and the brakes were working fine again, and so was the taillight. What is this "hummmm" and where is it coming from?

The brake magnets can make something of a humming/clanking noise as the brakes are applied, and this may be what you heard. You may have also heard one of the electrical devices in the trailer humming as the 12-volt feed from the tow vehicle can energize the trailer's interior 12-volt system through the umbilical cord. This to me, would raise the suspicion of a loose connection, corroded terminal or dirty terminal that was jarred back into operation when the cover was removed.

Originally Posted by 1hank1

Is there a wiring diagram available online detailing the braking system of my trailer?

There is a very rudimentary diagram of the system in your owners' manual. While there wasn't a factory service manual for the 1971 model year, one was published beginning in 1972 which would be a very close match for you 1971 . . . see this link to the Airstream Company Store.

Originally Posted by 1hank1

And lastly, I would like to replace all the rusty components of my tail light assemblies. Is there a "kit" to do such a thing?

Many of the components are available from parts stocking dealers such as Inland RV and Out of Doors Mart, and parts are also available from Vintage Trailer Supply. Depending on what parts are needed, it may be more economical to upgrade to LED tail light and running light components. LED lighting upgrades . . . both interior and exterior . . . have been popular recently so there have been a number of threads on the subject. I upgraded my Overlander to LED tail lights three years ago and have been very pleased with the outcome. Today, it seems like LEDs for RVs is one of the more popular sources for LED components and kits for RVs. Super-bright LEDs is another source of LEDs for our coaches that is mentioned in a number of threads.

Good luck with your investigation!

Kevin