Tail Light (update: Resolved)

Hi, I may need to replace my left tail light. Before I purchase/pull out the existing one though, I see from the owner's manual that the part needed is the entire module (rather than just replacing a bulb).

When a tail light module quits working does it stop working completely or can it still have partial function? I currently have partial function on the left tail light. The left tail light illuminates when the vehicle's headlights are on but I don't have a left turn signal and no hazard light function. I can't comment on whether the brake light or back up light works (solo sleuth here).

I've already narrowed down the issue to the trailer (my tow vehicle isn't the problem) and attempted to clean the connector site, but no go.

 

The tail light module is simply held into the aluminum skin with a giant grommet; getting it out is pretty easy, work a putty knife or something under the grommet and work it out. Getting it back in is a bit more fiddly, but putting some dish soap on the grommet will help it skoosh back in. The module unplugs from the trailer harness, there is a connector on the back. The LED modules are pretty reliable but can fail. If you pull it out, you can check for voltage at the module connector which will isolate it to the module or elsewhere in the harness.

Good luck!

 

With 2 flat bladed screw drivers you can pop that module out of the socket and test the wiring and/or the module.
A test light and/or a volt/ohm meter would be helpful. (I hope there are enough forward slashes in this sentence.)

 

Once out you can use a voltmeter to test the wires to see if you are getting power. You could also take both out and switch to see if the problem moves with the light. If so you know the light is bad. I agree getting back in is tougher.

 

Good advise. Nothing worse than loading up the parts cannon to find out that the part didn’t fix the problem .

edit: In my repairs a good volt/ohm meter is essential. Testing voltage and resistance of parts is critical to good diagnosis.

 

Thank you for the helpful comments. I don’t have a voltmeter, so I'll either start by getting one or swap out the lights to see what happens. Great suggestions. Thanks.

 

A 12 volt test light is about 11 bucks.
Well worth the investment if you pull a trailer.

 

A cheap one costs 25 bucks…, and generally will do everything you’ll ever need. Knowing how ohms, volts, watts all relate to each other is essential…here are tons of videos explaining it. I suggest those before you buy a tool. Not understanding how hey work won’t help you in diagnosis. The good news is, it’s all prettty simple. I understand it, and I could barely pass my math classes in school.

A test lite will work too….both are even better. The best tool though is the one between you ears. That is one that you need to focus on first.

if you need video recommendations, let me know…I’ll find the ones that help me the most.

 

Sadly, the tool between my ears is defective and past its best before date .

Seriously though, I do plan to spend some time with You Tube for Dummies to pick up whatever I can about it. When tackling something new to me, I usually do try to understand as much as I can about the task first, get a good sense of what is required and then decide if it is something that I should tackle on my own or not. I suspect this one will be on my can do list, but it is too soon to say for sure just yet.

Thanks for the advice.

 

It’s a bit much for a campinn…there just isn’t that many complex systems, you don’t have water heaters, slide outs, control boards (unless you have a furnace)

The rv tech in a box ,you may have seen it advertised, has a fantastic segment on ohms law….it really isn’t hard, especially if you are even remotely good at algebra….look up ohms law. Play with the numbers. When you realize a 1200 watt hair dryer pulls 10 amps… you’ve got it….unless your campground voltage sags to 104 volts …now it’s pulling closer to 12….it all suddenly gets interesting

but fortunately for diagnosing a tail light….it’s really not that hard . Look for around 12 volt …and you’re good

 

Thanks to everyone who helped me out with this post. The tail light is now fixed.

To answer my original question: is it possible to have a tail light module partially fail? YES. Replacement of the tail light solved the problem. Full tail light function is now restored. Easy removal and replacement just as everyone said.