Tail lights illuminated unexpectedly

[Dennis C.]

I pulled into a campsite today after about four hours on the road in rainy conditions. As I walked around the coach to check for clearance to open the slides, I noticed that the tail lights were illuminated even though the coach was parked in neutral and the headlights were in the “off” position. I’ve never seen this before. When I shut everything down, they turned off. What could this be? Could water have gotten into the wiring and shorted an electrical connection? Maybe an issue with the Freightliner smart wheel controls? I’ll check it tomorrow and see if the issue remains.

I’d appreciate any thoughts or comments.

[TandW]

Could it have been the brake lights? Can you push down on the brake pedal and ease it back up slowly to see if maybe the switch is nearly out of adjustment or the pedal isn't returning completely?

[Dutch Star Don]

By law, when you turn on your wipers, it automatically turns on your lights, headlights and taillights.

On older models, once you turn on the wipers the headlights went on and stayed on until you shut the coach down. On my 2019, when I turn on the wipers, the lights come on, but they can be turned off by turning the headlights on and off again. That way if it quits raining, you can shut the lights off.

[spuds]

Originally Posted by Dutch Star Don

By law, when you turn on your wipers, it automatically turns on your lights, headlights and taillights.

On older models, once you turn on the wipers the headlights went on and stayed on until you shut the coach down.

OP has shut the coach down. That's why he/she is asking - why the tail lights are still on. One would think that even if the wipers had been in use, once the engine is off, etc., the lights would go out. And it sounds like the headlights aren't still on, just the tail lights.

Perhaps a relay is stuck or got wet. We've seen that before with clearance lights turning on by themselves or not shutting off.

[Dutch Star Don]

Originally Posted by spuds

OP has shut the coach down. That's why he/she is asking - why the tail lights are still on. One would think that even if the wipers had been in use, once the engine is off, etc., the lights would go out. And it sounds like the headlights aren't still on, just the tail lights.

Perhaps a relay is stuck or got wet. We've seen that before with clearance lights turning on by themselves or not shutting off.

I noticed that the tail lights were illuminated even though the coach was parked in neutral and the headlights were in the “off” position.

When I shut everything down, they turned off.

His statement leads me to believe that the engine was still running. He didn't say he shut down the coach. I guess we'll see.

[ScotS]

Originally Posted by Dutch Star Don

By law, when you turn on your wipers, it automatically turns on your lights, headlights and taillights.

FYI, this is not a requirement in every state. I know that here in TX, headlights are not required with wipers, I think it's a good idea none the less. It is a programmable option on my truck and car, and I have it turned on.

Here is a fairly recent article on the subject.

https://www.wkyc.com/article/weather...5-8dfa0546eb1e


With the recalls on the rear PDM (tail light controller), it could be a PDM failure.

[Dutch Star Don]

I think that enough states required it thar the RV manufacturers implemented it so their coaches were 50 State legal. My 2005 Diplomat had them.

Sent from my SM-S916U using iRV2 - RV Forum mobile app

[Rob_M]

Don is probably correct, the OP simply didn’t notice his headlights were on also. My 2002 AC, when wipers are turned on, all lights come on and after turning wipers off I have to cycle the headlight switch to make the lights turn off as long as it’s still running.
Also the daytime running lights (dim headlights) come on when the parking brake is disengaged, but they go off as soon as it is set again. .

[Dennis C.]

Thanks everyone. I didn’t even look at the headlights because I walked around to the rear of the coach. The engine was running. I was simply surprised that the tail lights were illuminated because the headlight switch was off. Functionality related to the wipers makes sense. I had the wipers on and off for most of the day.