Forum Discussion

mildkiller's avatar
mildkiller
Explorer
May 14, 2014

URGENT! Rockwood 2318G doesn't have any signal lights on

Hi gurus,

I have a one year new tent trailer Rockwood 2318G. It's been functioning perfectly last year. Yesterday I pulled it out from an indoor storage and realized two things:
1. The battery was drained because I forgot to remove it. Now it's been recharging.
2. All signal lights don't work except the left side break light.

Symptom: when step down the break, only the left side break light is on, the right one is not. try the left and right turn signal, no light on. try the evening running light, no light on. the electric break controller has a green light that should indicate the connection is ready. it's off too. So I had to tow the trailer back without electric break and turn signal...

I check the 7pin plug diagram but still can't determine the issue is on the vehicle or the trailer. Anyone can help with step-by-step instruction? I have a volt meter. How can I test the 7pin plug on my Odyssey? For example, when give out the left turn signal, how much voltage can be read on the plug? The tow package, electric break and all wiring were installed at U-Haul and no issue last year. Really have no idea why it suddenly has an issue without any change on both vehicle and trailer.

Thank you for help!
Daniel

15 Replies

  • Regarding your first paragraph. Yes, pin 4 is the +12VDC circuit. When connected, your tow vehicle will charge the trailer battery.

    I would not suspect a bad ground since your left brake light was working.

    You should have about 12.7 volts for the turn signals, brake lights, running lights etc.

    If you have good connections at the truck and trailer, then check the bulbs themselves. Make sure each bulb is in good shape, and use your meter to make sure you have voltage at the light sockets. Make sure your light bulbs do not have corrosion on the terminals. If so, clean the terminal and the bulb and check again.
  • thank you, gents!

    In such a rainy day, I didn't get a chance to fully test connections but I did test the trailer side according to the plug diagram (trailer). Several Ohm(resistance) can be measured at each pins(for lights) except Pin4(aux 12V) has 12V output, which I believe it comes from the battery. Is it correct? When it connects to the vehicle, the Pin4 connects to vehicle's pin4 that is 12V too. Does it the mean the battery on trailer get recharging from the vehicle?

    At this point, I feel no issue from trailer. I will test the vehicle side later. Usually I will test the voltage output at each pin while giving the relative function but I don't know how much voltage it supposes to be for the L/R turn light(pulse?), stop lights, running tail lights and break signal. If there's a bad ground, I should read lower voltage or nothing?

    Thanks again,
    Daniel
  • RoyB's avatar
    RoyB
    Explorer II
    I always squirt some WD40 into the truck side connectors and wiggle around some to make a good connection.

    I also have one these in my RV TOOL BOX which plugs into the truck side trailer connector and this will tell you if the proper signals are being generated from the truck side. Helps you troubleshoot better looking for the cause of the weird lights coming on.. I got mine from AMAZON but have seen them for sale at regular truck parts/accessories places..



    Roy Ken
  • Welcome to the forum.

    I am thinking that there isn't an issue with your trailer as an issue with your tow vehicle. The reason, the left brake and the left turn signal work on the same pin/wire/bulb. So, when you step on the brakes, and only the left brake light will come on, the left turn signal should also flash.

    Does your vehicle have a factory tow harness and plug, or did an RV shop add what was needed. My vehicle didn't come prepped since I bought it used, so I had to wire everything myself including a converter box.

    Also, living in salt country, I have to change my rear plug every spring due to salt corrosion. You could have issues there, too.
  • Sorry to hear about your issues. I know it can be frustrating.

    1. First, visually inspect your trailer and tow vehicle connections to see if there is any corrosion, debris or dirt. If so, correct and recheck your lights.

    2. Check out your tow vehicle connections to make sure they are functioning appropriately. Use your volt meter. I've attached a wiring diagram below so you can check from point to point. If you don't have a good connection, you need to trace it back to the issue.

    If you can't find the issue with these two steps, report your results so we can help you further.