Trailer Lights pulse

J

Jhayes

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Sep 26, 2012
Messages
15
I just put a new set of lights on my trailer, wiring was done as well. When I was testing the turn signals I noticed the oppisite light had a slight pulse to it. The wiring is new on the trailer and I never noticed this before with the old lights. I do not have anything crossed, all splices were soldered and heat shrunk. The tow vehicle is a 99 4Runner that has a Hopkins taillight convertor(vehicle has seperate turn signal bulb). Any ideas on what to do next? Is it possible that the plug on the new lights is defective and leaking juice to the oppisite light/

Thanks all
Jeremy
 
aspeck

aspeck

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Re: Trailer Lights pulse

Check your grounds to make sure all are secure and correct.
 
J

Jhayes

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Re: Trailer Lights pulse

The grounds should all be perfect, I used my ginder to cut to bare steel at both lights and the tongue. I tested the tow vehicle with a test light and nothing hooked up, all tested as they should. I then hooked the trailer up leaving the plug open enough to fit the probe, with the left turn on and brakes on the right turn/stop pulses slightly, with the brakes off it works as it should. The trailer is only connected by the wiring harness, I do NOT have it on the ball of the truck. I will go try hooking the two together to see if that makes any difference

I hate lights, ugh.

Jeremy
 
aspeck

aspeck

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Re: Trailer Lights pulse

Jhayes said:
I hate lights, ugh.
Click to expand...

:D I feel your pain. It could be a back feed through one of the sockets that you replaced. If grounds are good, then there is the backtracking to see there the back feed is coming from. You are going to have to see test for continuity to find where the leak is coming from. And that is never any fun.

I always get shocked when working with electricity, so I am not the best one to be giving you advice! :eek: LOL!
 
B

batman99

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Re: Trailer Lights pulse

If new wires, connections are soldered and shrink wrapped and Tow Vehicle's connector is good, I'd focus on:
- Ensure the wires are properly assigned - to Tow Vehicle plug. Use a 12V Probe tester to test both male and female of the connector. Also, make sure the wiring pin assigments are from the correct view. Meaning, the pins in the connector aren't assigned backwards (as if looking with instead of "looking at") the connector. If wondering, I miss-wired a connector this way once. Very weird results - unitl fixed.
- Also investigate the light assembly bulb sockets. If removable bulbs, ensure dielectric grease is manually applied to the base of each bulb (for better correction, better current flow and it reduces electrical corrosion). Simply wipe some on the bulb's base with bare hands. re: http://www.youtube.com/watch?v=8W7o-CRRmGo
- Also investige if your Tow Vehicle needs Heavy Duty Flasher upgrade. Some trailers need HD flasher module installed in TV (under its dash).

Hope these help as well...
 
H

H20Rat

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Re: Trailer Lights pulse

Start the vehicle up and try it again...
 
J

Jhayes

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Messages
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Re: Trailer Lights pulse

I found the problem, there it was right on the package "Made in Taiwan" !

One would think if they bought new everthing, wired it properly it would work properly, frustrating!

I pulled one bulb and check continuity, none between L & R stop/turn, continuity was there when bulb was in, which makes sense since they need ground to work. There is no dielectric grease on them, I only have silicon grease on hand, can that be used instead? The old lights never did this, I only replaced them because the housings were broken.

When I do get this figured out can I spray paint the spots I sanded bare for ground?

Jeremy
 
J

Jhayes

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Messages
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Re: Trailer Lights pulse

I just tested a set of emergency magnetic tow lights, same results. If the brake is on and the right blinker the left light dims slightly when the right is blinking. So where to next, replace the flasher in the TV or the taillight converter or both? the TV has 170,000 miles so I'm guessing the flasher may be the weakest link. I may replace the TV 4 flat lead because I have one on hand.

resulsts were the same if TV was running or not.

UGH, lights

Jeremy
 
B

batman99

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J

Jhayes

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Messages
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Re: Trailer Lights pulse

batman99 said:
If I remember correctly, some Tow Vehicle's that use seperate Brake and seperate Turn signals (on the Tow vehicle) need a small convertor box (in the Tow Vehile) for attached trailers. re:

http://www.etrailer.com/Wiring/Tow-Ready/119130.html
http://www.etrailer.com/Custom-Fit-Vehicle-Wiring,Wiring/Hopkins/HM48915.html

re: Adapts import and domestic vehicles with separate turn and stop lights (3-Wire System) to standard trailer taillight wiring (2-Wire System).

.
Click to expand...


You are correct. Mine came factory with one that failed eventually. It was replaced with a Hopkins one, might be time to replace it again. I feel dumb, but I cannot find the flasher in my TV, I know what they look like, just cannot find it.

Jeremy
 
Bob's Garage

Bob's Garage

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Re: Trailer Lights pulse

Do you have available a friend with a tow vehicle that you can use to test your trailer? It may be that the converter is malfunctioning.

When i rewired my trailer I also soldered the connections but I went one step further and ran a separate ground wire to the tail lights. I still had the trailer ground for the side lights, which are chassis grounded, but it took the tail lights off the common ground. The lights work perfect and there is never a question as to the value of the ground.

So my suggestion is: test your trailer with another vehicle, and or move the lights to a dedicated ground.

(If I was to make a guess I would expect to find a bad ground, regardless of your continuity test, and one of your lights is grounding thru the other. Alternately take out one of the bulbs and see which one doesn't work by itself.)
 
J

Jhayes

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Sep 26, 2012
Messages
15
Re: Trailer Lights pulse

Bob's Garage said:
Do you have available a friend with a tow vehicle that you can use to test your trailer? It may be that the converter is malfunctioning.

When i rewired my trailer I also soldered the connections but I went one step further and ran a separate ground wire to the tail lights. I still had the trailer ground for the side lights, which are chassis grounded, but it took the tail lights off the common ground. The lights work perfect and there is never a question as to the value of the ground.

So my suggestion is: test your trailer with another vehicle, and or move the lights to a dedicated ground.

(If I was to make a guess I would expect to find a bad ground, regardless of your continuity test, and one of your lights is grounding thru the other. Alternately take out one of the bulbs and see which one doesn't work by itself.)
Click to expand...

Good idea, My wifes SUV has a tow package, I'll try that tonight as well. I was thinking of running ground wires to them all anyway, the side lights will need them anyhow. Getting the ground wire down trough the frame to the tails will probably require redoing the tail connections, I have no fish tape.

Jeremy
 
G

glenn property of pam

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Feb 17, 2012
Messages
2,906
Re: Trailer Lights pulse

most likely a week ground on the truck side plug either at the connector or the wire thats grounded to the truck. when the brake lights are used the ampage is to high to return on the ground due to a bad connection on the truck so some of it trys to find another path to the battery via the turn signal on the other side of the trailer to the trucks turn signal then to ground.
 
Thalasso

Thalasso

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Re: Trailer Lights pulse

bigdee said:
If it won't I don't know what will. The 2012 Tundra has the highest towing capacity of anything out there......25000Lbs with a class V fith wheel hitch!!
Click to expand...

What does this have to do with wiring problems?? 25000 lbs I don't think so I have one. Fifth wheel towing is dependent on payload specs and there isn't any pickup rated for 25000 lbs
 
Thalasso

Thalasso

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Messages
2,876
Re: Trailer Lights pulse

You can always use a set of jumper cables to make the ground from the TV to the trailer. Ground on a good spot on TV frame to trailer frame
 
J

Jhayes

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Joined
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Messages
15
Re: Trailer Lights pulse

Ground seems good as there was no real change when using jumper cables to assist ground. The wire on the new lights seemed light in gauge to me, I have to use the 18-20 slot on my stripper to get the wires preped for soldering, could this light gauge be an issue, although the emergeny magnetic lights acted the same, light wires on those too. I plan on putting in a new converter or at minimum a new conector on TV and grounding the converter to the TV body as well as the wire thats there.
GRR, lights


thanks
Jeremy
 
B

batman99

Petty Officer 1st Class
Joined
Sep 13, 2012
Messages
393
Re: Trailer Lights pulse

For my trailers, I always use:
10 Guage for brake wiring.
12 Guage for all lighting.

If wondering, 12 Guage wiring has much thicker outer casing - compared to thin 18 guage wiring. Thus, better in-frame vibration wear and better water exposure. And where possible, feed wiring into plastic loom ( http://www.princessauto.com/hlr-system/WebPhotos/82/820/8209/8209256.jpg ) - to create even more outer rub protection...

I like Bob's Garage idea of connecting your trailer to a different Tow Vehicle. And, connecting a known working trailer to to your Tow Vehicle. If problem follows your trailer, then its your trailer. If problem follows your Tow Vehicle, then its your Tow Vehicle. This would be my 1st test - before buying any replacement parts.

Hope this helps..
 
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