problem with exterior lights

[Marsha]

Ok guys, I have a good one for you... put on your thinking caps!

I have a 2008 Jayco Seneca we bought it used this winter and we have been cleaning it and starting to outfit it. We noticed that when we turn on the headlights, we have NO other lights! No Taillights, no sidemarker lights, no clearance lights. we have brake lights, flashers, directionals and backup lights. we have checked the fuseblock under the dash, they all look fine, we checked the fuseblock under the hood, they all look fine. is there a wire/cable along the chassis that we can check? I dread bringing this monster bck to the dealer before our first trip. Any Ideas?

[THE MEEKER]

Go with the most simplest solution first, which is to clean the connection from trailer to tow vehicle.

Clean the 7 way male plug on tow vehicle and 7 way female plug on trailer. I would use Ballistol if you have handy, or WD40. wipe clean, use a small file or sandpaper to clean connections. Then put the plug into the tow vehicle recepticle in and out 3 or 4 times, then plug in, check all your lights.

[Marsha]

thanks for the idea, but it’s a class c motor home. i would love it if it was simple.

[DonaandDon]

What lights do you have without operating the headlight switch?
- Flashers?
- Brake lights?


When you open the door do any clearance lights come on?

Are you draining the batt when the headlight switch is on?

Have you felt for a warm/hot wire? Under the dash?

Does your license plate light come on?


And of course good luck...

[RVermont]

I had the exact same issue with my 2018 Seneca so this might help but since they changed chassis not fully sure but worth the investigation.

On my unit I lost the ground on the rear of the chassis. This ground is the one that handle ceiling lights and marker lights. As well as ceiling fan. Since the chassis head lights control the marker lights the ceiling lights which are very low amperage were grounding through the chassis ground. When the head light get turned on the other lights have a difficult time going to ground and they simply stop working.

I rebonded the ground and all is good with the system now.

Again not sure on your coach but all the overhead wiring runs down the rear cap. Check for bad ground in that area.

To quickly check if it a bad ground open one of the non working lights and run a wire to ground. If that fixes it you will have to locate the missing link.

Good luck.

[Marsha]

thank you. we will have to check that.

[Marsha]

What lights do you have without operating the headlight switch?
- Flashers- YES
- Brake lights YES


When you open the door do any clearance lights come on?
NO

Are you draining the batt when the headlight switch is on?
NO

Have you felt for a warm/hot wire? Under the dash?
NO
will have to check this

Does your license plate light come on?
NO

thanks!

[ALJO]

Ground connections is one of the biggest problems with vehicles, RV's etc. Usually because of poor install and maintenance. While the chassis is the flow of the negative of low voltage (12 volt) and the flow of the neutral and ground of the higher voltage (120 Volt).

Never assume a fuse is good and in working condition by looking …......test it with a light tester or multi-meter.

[Marsha]

thank you