Electrical Gremlin...Help

[sailorii]

Have a 2009 28' Flying Cloud. When I hook the power cord to the truck, all lights on the trailer work with the exception of the upper left tail light. I drive a few miles and it starts working.

Suspected the connections at the plug in at the truck. Cleaned up and polished truck and trailer side connections-didn't fix it(but, it made every LED on the trailer about 100% brighter!). I put a jumper wire across the plug on the trailer that makes all lights burn and the upper left tail light works. So, now I'm stumped.

Any electricians out there that can help me run down this problem? Would appreciate the basics/detail/order of checking-I'm not good at diagnosing electrical. I have been told that getting the individual lights out of the aluminum casting on the back of the trailer is very tough-any suggestions in this regard if this is going to be something I'll need to do.

Thanks folks.

[HowieE]

If any of the tail lights work it is not the connection at the truck because that connections feeds all of the tail lights.

The problem is in the fixture of that light. The fact that it comes and goes you should be able to find the problem by opening the fixture and while the lights are turned on tap the bulb. This will check the filament of the bulb. If that is not the case wiggle the bulb. That will test the socket. If that is not the case remove the fixture and while holding the fixture to the trailer body for a ground wiggle the wire connections to the fixture. The fixture ma have been grounded by the screws that hold in in or there may be a separate ground wire. If so check that connection.

If none of this shows the problem you have a loose wire connection in the wiring leading to that fixture. But I think you will solve the problem before this point.

[Inland RV Center, In]

Originally Posted by sailorii

Have a 2009 28' Flying Cloud. When I hook the power cord to the truck, all lights on the trailer work with the exception of the upper left tail light. I drive a few miles and it starts working.

Suspected the connections at the plug in at the truck. Cleaned up and polished truck and trailer side connections-didn't fix it(but, it made every LED on the trailer about 100% brighter!). I put a jumper wire across the plug on the trailer that makes all lights burn and the upper left tail light works. So, now I'm stumped.

Any electricians out there that can help me run down this problem? Would appreciate the basics/detail/order of checking-I'm not good at diagnosing electrical. I have been told that getting the individual lights out of the aluminum casting on the back of the trailer is very tough-any suggestions in this regard if this is going to be something I'll need to do.

Thanks folks.

A tail light bulb, has 2 contacts at the bottom of the bulb.

Sometimes, the tow solder domes are not equal height.

Pull the cover, pull the bulb and check it out, as well as the connector within the base.

Andy

[sailorii]

Thanks, HowieE. These lights are the factory LEDs. Does this change anything regarding your thoughts? Also, would sure like to know how to get that individual fixture out of the casting-no visable fasteners and it looks fragile. Any ideas on that?

[Rich W]

It definitely sounds like a bad connection, most likely at the light itself. Since it works sometimes and sometimes not, the LED must be good but the plug that goes into it must be dirty or corroded.

I'm not sure about how to remove it but if you go to the Airstream web site, look for the support link (you need the last 4 of your VIN) you can ask them how to remove the light and check it. They are very good about responding. I get a reply in anywhere from 1 hour to 1 day.

[HowieE]

Yes

You are down to a bad connection if LEDs are involved

I do not know how to remove the LED assembly from the fixture, I made my own, but it can be done. Once you get to the wires between the trailer and the LED assembly check the connections. If not there it could be a broken ribbon on the printed circuit board of the LEDs itself. About all you can do is test for voltage with a voltmeter leading to the assembly. If you have a constant source of voltage I would think it is a bad LED assembly.

[mimiandrews]

Could be a dirty or corroded ground connection for that particular tail light. Either there will be a wire from that tail light housing attached to the metal structure of the trailer, or the circuit will ground by contact between the light housing itself and the trailer skin or frame.

Inspect those areas for corrosion, dirt, or loose connections and see what you get.

From what you've told us, you've isolated the problem to that one light. That means something is loose or dirty going into or coming out of that light assembly.

Good luck!