Brake light/ turn signal

[tensch]

I am having an issue with the passenger side turn signal and brake light not working on a 1993 Coleman pop up. The running light is working. I'm just wondering where to start with this and maybe there is a simple fix or test? It is a 4 pin connection and I have replaced the bulb. Thanks.

[opnspaces]

Glad you got it fixed. And thanks for coming back with an update. I'm sure I'm not the only one who periodically checks threads he's made suggestions on to see the outcome. 🙂

[tensch]

Turns out it was broken wire at a plug that was about 3 feet from the 4 pin connector. It was wrapped in electrical tape so previous owner must have done a band-aid fix. Bought a new plug and everything is working. Thanks for all the help!!

[BarabooBob]

Do yourself a favor. Run new wires and change your camper lights to LED fixtures. The total bill if you do it yourself can be as little as $60. I personally solder all of my connections and use heat shrink tubing to seal everything up.

[Terryallan]

cavie wrote:

Terryallan wrote:
Agree check the bulb. however you said the running light is working. But that doesn't tell you the brake light is working. The brake light, and the turn signal light is the same bulb. has 2 filaments in one bulb.

tail light is one filament. Brake and turn is the other.

Ain't that what I said???. Guess I wasn't real clear.

[enblethen]

OP: Did you check for fuse in the truck? Each function has a separate fuse.

[cavie]

Terryallan wrote:
Agree check the bulb. however you said the running light is working. But that doesn't tell you the brake light is working. The brake light, and the turn signal light is the same bulb. has 2 filaments in one bulb.

tail light is one filament. Brake and turn is the other.

[beemerphile1]

Use a meter to determine if the signal is actually reaching the socket and report back.

The most common running/brake light problems on a trailer are bad grounds.

The brake/turn bulb filament is higher amperage and requires a solid ground connection.

[opnspaces]

As far as simple tests, it kind of depends on your skill level and available resources.

Do you have a couple of alligator clip test leads? If so unplug your 4 flat plug and use one test lead to connect the ground pins to each other. Use the second test lead to see if the tow vehicle yellow (left turn) wire can blink the right turn by connecting from yellow (TV) to green (PU) If the light blinks the problem is in the TV, if the light still does not blink the problem is in the trailer.

[opnspaces]

I'll bet the cheap light socket is not touching the base of the bulb. Try putting the turn signal on and then go push the bulb tighter into the socket. you can also remove the bulb and look down into the socket. It might be possible to bend the two electrical tabs up a bit so they make better contact when the bulb goes in.

I had a similar issue in on my 1986 and I could temporarily fix it by bending the tabs. In the end I had to pull the whole back panel down and replace the lights with some LED taillights.

[Terryallan]

Agree check the bulb. however you said the running light is working. But that doesn't tell you the brake light is working. The brake light, and the turn signal light is the same bulb. has 2 filaments in one bulb.

[cavie]

START WITH THE BLUB.Turn and break are the same filament of an 1157 bulb. Unplug from TV and check TV plug. Disconnect trailer wiring from light. Plug in TV and check trailer wiring. Yellow and green are turn signal. Red is brake, white is ground.

[enblethen]

What is the tow vehicle?
If it is the F150, check for blown fuse in the fuses under the hood.

[YC_1]

Get a cheap 12 volt test light. Less than $10 and more forgiving when chasing tail light.

You need to make a good ground somewhere. Use a scrap piece of wire if necessary. Once you have the alligator clip connected to a good ground you can probe the socket first since you changed the bulb. You could easily have purchased the wrong bulb or not have it inserted properly. A simple test is to remove the same bulb from the left light and put it in the right side. Test your old bulb in the left side as well.

If you still have the issue then you should really start at the trailer plug side of the tow vehicle. Could be a blown fuse in the towing vehicle.

You need to be careful to not introduce a new problem while trying to diagnose this one. Take pictures as you go and print some out. Document what you did.

[schlep1967]

Start with a multi-meter or test light on the vehicle side of the 4 pin connector. If all is good there try cleaning the 4 pin connector. After that, a quick visual inspection of any wiring you can see for cuts or breaks. Then do as stated above, run new wires.