Tail Lights: Flashing Slowly/Performing Poorly

[bgordon]

I cleaned up all the connections/bases and have all my running lights in good order.

I tested them via connection to a 12v battery and they all light up quite well. Then I went to tow and am having an issue between the TV and the trailer. With the turn signal on the light only lights up very briefly and does not reach full power. I am using all incandescents right now and the main stop/tail/turn light is with a dual contact 1156 bulb.

The lights on the tow vehicle flash correctly but it just seems like to short of an off/on duration for the additional wire length and 1156 bulb. The bulb only manages a portion of the brightness compared to hooking it up directly to 12v to test.

Is this a common problem? It seems like an easy fix might be to put an LED bulb in which has a much quicker on/off ability. Any thoughts?

[TG Twinkie]

Sounds to me like you need a heavy duty flasher.

[HowieE]

If you are saying that while hitched the trailer lights flashing at a different rate than the TV there is no answer for that. The rate is determined by the flasher in the TV.

Now that said the brightness of the trailer lights is a function of the voltage applied to them. Voltage can be effected by the condition of the contact through the system and the condition of the ground connection. Try reading the voltage at the light with a analog volt meter. I say analog because most digital meter will not react in time to a short duration signal. If the voltage is low start checking voltages back though the wiring that supplies the lights till you see 12 volts and clean or replace the connection that is dropping the voltage.

[bgordon]

The lights flash in accord with the TV.

It seems that the flash duration is not long enough for the filament to reach its operative brightness.

[bgordon]

To reiterate, I tested the lights hooked up directly to a 12v source and the luminosity is great. There are new wires, new grounds, new bulbs, refurbished sockets.

The issue seems to be in the flash duration. Hence, why I was thinking led bulbs might solve the issue as they react quicker to changes in voltage.

[robert claus]

If your TV has separate turn signals and brake lights, then there is a converter in the wiring that makes the TV wiring work with the trailer that would have combination brake/turn lights. I went through a couple of TV factory converters before splicing in a better unit. My lights were dim, and sometimes would only work on one side, and brake lights wouldn't work sometimes, after driving for a few minutes. They'd look fine doing a light check before leaving, then we'd find we didn't have lights later. The converter would fail after heating up. Maybe you have a converter problem, too.

[HowieE]

I am not familiar with the convertor Robert mentioned but in either case you have a voltage drop. Light react too fast for it to be a warm up consideration.

Find the voltage drop problem before you go to LEDs as the will not fire under low voltage conditions.

[vswingfield]

Have you tried the heavy duty flasher TG Twinkie mentioned yet? In the past, I had two vehicles that wouldn't flash at all till the original flasher was replaced with a HD one.

[richinny]

howie mentioned the truck flasher. if it is a light duty flasher the rate will speed up depending on load. if the flasher has a good rate without the trailer but speeds up when connected you probably have a light duty flasher or a short.

[Tumajin]

What TV are you using? Some vehicles have ECU's that are sensitive to external trailer electrical connections. eTrailer has an adapter that hooks between the TV and trailer socket/plug which solves the mismatch.

[Splitrock]

When I got my trailer, the exterior lights were messed up. Some worked, some didn't. I replaced all the running lights with LEDs in new fixtures. I replaced all the bulbs in all the other lights, even if they worked. I replaced the lenses on the rear lights. I got a 7-way tester, a small battery charger, a 12 volt jumper test light, and a small multi-meter.

One thing that helped a lot was my decision to make double sure I had good grounds. I twisted all the grounds to a new #10 wire lead, plumber's fluxed the twist and soldered them all together with my map gas torch. Then I cleaned a new contact point and attached the new lead to the coach body.

I made up a new fuse panel, installed a new 7-way trailer plug, a new breakaway switch, and a new umbilical cord. I tested the tow vehicle with the tester and all was well. When I installed the cord, I had the back up lights switched with the charge line on the cord end. I reversed those two wires and everything lit up bright and right.

,

[Dan@LED4RV]

Originally Posted by bgordon

I cleaned up all the connections/bases and have all my running lights in good order.

I tested them via connection to a 12v battery and they all light up quite well. Then I went to tow and am having an issue between the TV and the trailer. With the turn signal on the light only lights up very briefly and does not reach full power. I am using all incandescents right now and the main stop/tail/turn light is with a dual contact 1156 bulb.

The lights on the tow vehicle flash correctly but it just seems like to short of an off/on duration for the additional wire length and 1156 bulb. The bulb only manages a portion of the brightness compared to hooking it up directly to 12v to test.

Is this a common problem? It seems like an easy fix might be to put an LED bulb in which has a much quicker on/off ability. Any thoughts?

The ground runs the full length of the unit. First at the plug, inside and out, where the cord connects to the unit. Then to where the ground connects to the light housing (any number of ways that it could be done). A little corrosion at each connection can add up. To disprove the ground idea you could run a jumper wire from inside the 7 way plug and plug into the tow vehicle. Then attach to the inside of the light to the lights ground. Then test your lights from the vehicle with the engine running. It should be brighter than your 12 volt battery test. If the brightness makes you happy you have a bad ground.

[ROBERTSUNRUS]

Originally Posted by bgordon

I cleaned up all the connections/bases and have all my running lights in good order.

I tested them via connection to a 12v battery and they all light up quite well. Then I went to tow and am having an issue between the TV and the trailer. With the turn signal on the light only lights up very briefly and does not reach full power. I am using all incandescents right now and the main stop/tail/turn light is with a dual contact 1156 bulb.

The lights on the tow vehicle flash correctly but it just seems like to short of an off/on duration for the additional wire length and 1156 bulb. The bulb only manages a portion of the brightness compared to hooking it up directly to 12v to test.

Is this a common problem? It seems like an easy fix might be to put an LED bulb in which has a much quicker on/off ability. Any thoughts?

Hi, either you made a mistake in numbers or you are using the wrong bulb. You should be using an 1157 dual filiment dual contact bulb.

[bgordon]

I did mean to write that the rear lights are an 1157 bulb - not 1156.

The tow vehicle is a 1993 Toyota pickup. I haven't looked into heavy duty flashers but I will. The flash cycle appears normal when the trailer is plugged in. I haven't tested with a volt meter yet - I only have a digital model.

My previous test was hooking up the trailer plug to a 12v battery and all the lights worked great and had acceptable brightness. I recently completely overhauled all the wiring and lights. Everything on the trailer side is working great. I just noticed that when hauling it most recently that the brighter filament didn't cycle on that long or bright.