jOne of the turn signals on my newly acquired 2013 Rockwood pop-up doesn't work. The running light is fine but the brake and turn signal don't do anything. The two filaments in the bulb looked fine, but I hoped a new bulb would solve the problem; it didn't. I noticed one thing that surprised me: both the new and the old bulb will only fit in the socket one way. That is, the socket won't accept the bulb after rotating it180 degrees. The bulb is the kind with two filaments and two terminals on the base, with a regular bayonet mount. The base of the socket is spring loaded and seems to press up against the bulb well enough. Could the problem be with the newly installed brake controller and connector on my tow vehicle? It's a 2011 Toyota Sienna.Thanks in advance for any ideas!Gary

If you look at the base of the bulb I think you will notice that one of the pins on side of the base is lower than the other pin. That is so it only fits in the socket one way.I would check your grounds. If the light on the other side of the RV works then probably the ground at the light that doesn't work has the bad ground. Could be the ground or the socket itself. If neither brake light works I would suspect the plug or socket in your tow vehicle.Sometimes I have noticed the plug itself get corrodeded contacts. I have a utility trailer that I seldom use. My running lights will work but brake and turn signals don't work. I plug and unplug the socket into my PU several times and it usually corrects the problem. They have some contact cleaner in a spray can. Auto parts stores carry it. If all else fails I spray that on the contacts and plug and unplug the plug into my PU several times.

look at the brass part of the bulb the two prongs are at different levels ,they will only fit one way push down turn a bit , for your lights not working lets start simple .go to the tongue of the trailer remove the white wire bolted to the frame .clean the steel to bare metal new screw and install. now try them. MOST all trailer light problems are cussed by a bad ground. some where in the system.

In addition to a bad ground, it could be a broken wire or a bad connection for the brake/signal line. You could test this with a volt meter on the connections. Since it is both the brake and the signal for only one side, I'd think the issue will be found right at the light itself.

AS you know this can be in either location being the truck or the trailer. I always have one of these 7-way adapters (AMAZON-ETRAILER) in my tool to plug-in the truck side and make sure those signals are working correctly. Then I know where to start looking for the problems...7-way BLADE TESTERWire colors may be different depending on the manufaturer...Etrailer.com is a great source for wiring info for the RV trailers...My F150 Truck side 7-way connector has a pin-out decal on the side of the blade connections which helps big time when using a multimeter to check the blade readings...I usually squirt WD-40 into the 7-way connector before plugging in the trailer. This keeps the blade connections clean for me... Some folks like to use a compound from the auto parts places that probably does a better job then WD-40 for electrical connections. WD-40 works OK for me as I always carry a PLAN B fresh can of it in my door side pocket. I just do a couple of squirts of it and move the the plug around a few times and never have a dirty connection problem it seems... There is also a roll of duct tape in my side pocket as well haha...Might be hank of bailing wire there as well...Roy Ken

Check the tow vehicle for a blown fuse. many rigs have fuses that protect the trailer connector circuits. I cannot tell by your profile as to what TV is.If no fuse is blown, use a jumper from the pop-up trailer connector battery pin to the bad side turn signal. This should tell whether issue is in TV or pop-up.

Turn signal problem... | Good Sam Community

JLTN_James
Explorer
Sep 09, 2015
If it was a dirty connection, then it's one of two places: the bulb socket or the pigtail. My money is on the pigtail...

I'd recommend putting some "bulb grease" on all the bulb sockets and the pigtail. The grease is available at auto parts stores or Wal-Mart for a few bucks. One tube will last you well into your next two trailers! Clean all the connections with a stiff brush first. Don't forget to put some on the tow vehicle's lights and trailer connector while you're at it.

I'd also recommend opening up the trailer pigtail connector every couple of years to make sure those screw connections are tight. A little grease there wouldn't hurt either.

Glad to hear the installer bought back the Curt time-delay brake controller. You'll be much, much happier (and safer) with the P2.
Resoman
Explorer
Sep 05, 2015
Well, today I had the Tekonsha Prodigy P2 brake controller installed; the installer gave me credit for the Curt unit they had originally installed. I told the technician that I had a problem with the right turn signal and, half an hour later, he told me that he had found and fixed the problem: a dirty connection that he cleaned up with WD-40. I really hope he's correct; I should get to test the trailer lights this weekend though I won't be able to give the controller a test until I return from a trip.
So, let's hope he found the problem; thanks to all for your ideas!

Gary,
Elgin, TX
enblethen
Nomad
Sep 04, 2015
OP only has one brake/turn signal that is not working. Brake and turn signals for vehicle could be o0n same fuse, but on rigs with auxiliary fusing for trailer connector they (turn signal and brake) are on separate fuses.
jfkmk
Explorer
Sep 04, 2015
enblethen wrote:
jfkmk: That is not correct. The brake lights use the same wire and filament as the turn signals.
Many TVs have fuses that are for each turn signal.

My bad, what I meant to say is, the brake lights are protected by a separate fuse than the signals. So, it is unlikely to be a fuse problem, as both fuses would have to be blown.
enblethen
Nomad
Sep 04, 2015
jfkmk: That is not correct. The brake lights use the same wire and filament as the turn signals.
Many TVs have fuses that are for each turn signal.
jfkmk
Explorer
Sep 04, 2015
Resoman wrote:
Could a bad fuse allow the bulb to work fine for the running lights, but prevent the turn signal and brake light from working?

Yes, the running lights are on a different circuit than the brake lights. However, both brake lights are usually on the same circuit, so if one brake light works, that would rule out the fuse for the brake lights as the culprit. Additionally, since the turn signal also doesn't work, it would probably rule out fuses, as the turn signals are on a different fuse than the brake lights.

If it were me, I'd check to see if the bulb socket wiring is compromised. Might be a loose or broken wire right at the socket.
obgraham
Explorer
Sep 04, 2015
You just need to get out a long chunk of wire and start bypassing things. The fault will be soon evident.
Resoman
Explorer
Sep 04, 2015
Could a bad fuse allow the bulb to work fine for the running lights, but prevent the turn signal and brake light from working?
midnightsadie
Explorer II
Sep 04, 2015
kid had the same problem and its a fuse , dealer fixed it,same car.
enblethen
Nomad
Sep 04, 2015
Look in owner's manual for the fuse block if equipped under the hood for fuses to the trailer connector.

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