Rusty hitch ball = flickering lights.......

[wallytap]

Just a little reminder, had trialer lights with sporadic flickering......checked the wiring harness redid the ground to the trailer still flickered. So, some emery cloth on the somewhat rusty ball & coupler, problem solved. I know this is not news, just a reminder....it's nice to have shiny balls..................

[Hot Runr Guy]

You still have a ground circuit problem. The ball should be well greased-up, rather than dry and shiny. Either your ground at the vehicle end is bad, or I find a lot of trailers have a lousy ground connection back at the taillights. I've started running dedicated wires from where the trailer pigtail attach's to the frame, back to the taillights.
HRG

[wallytap]

How can I still have a problem if what was done corrected the flickering lights while driving down the road? The ball was rusty and harness wire ground redone at the coupler, coated the ball with WD 40. Should I pull the tailight lense & check the ground back there also?

[Hot Runr Guy]

If the clean ball corrected the "flickering", then the ground circuit is trying be accomplished thru the ball, rather than thru the wiring. Here's a fairly easy test to try. At night, connect the trailer plug to the tow vehicle, but do not drop the coupler on the ball, do not let them touch. Turn on the running lights, and then activate your 4-way flashers. If your running and side marker lights start dimming, or worse yet flashing, then the existing ground circuit is insufficient to do the job. Like I mentioned, I've started adding white ground leads from where the pigtail ground attach's to the trailer (by the coupler?) and running them all the way back to the tail/stop lights. This way, you are not relying on the trailer frame to be the ground.
But, that's just the way I do it.
HRG

[wallytap]

Thank You, will test tonight. Is it possible the truck ground is at fault or do these symptoms point to trailer "ground" problem?

[Hot Runr Guy]

it could certainly be the truck side. When you are running the test I described, take a piece of wire, and hold or clip 1 end to where your pigtail attach's to the trailer frame. Then, find a clean bolt head or something on the truck, and hold or clip it there. If the problem goes away, you've isolated the problem to either the connectors themselves, or the truck-side ground.
HRG

[yarcraft91]

...that you've already gotten here, I'll add that WD-40 isn't what you want as the lubricant on your trailer ball. Use good ol' chassis grease. Messy, yes, but it does the job.

[REW]

The other posts are right on.
The trailer ball is not the correct way to get a vehicle ground to the trailer.

The trailer ball is used to pull the trailer, not ground the lights.

As a matter of fact, trailer balls and trailer receivers should be kept well greased with wheel bearing or similar grease. Lots of pressure when pulling and the use of grease will minimize the friction on the ball.

The trailer lights ground - on the other hand, is carried from the tow vehicle to the trailer lights, by use of the "white" ground wire in the tow lighting harness.

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As the other post suggested - have the trailer near the tow vehicle, but not hooked to the ball. Connect the wiring harness and test all lights, for correct operation.

You need to have a good ground from the negative battery supply of the tow vehicle to the ground side of the bulb in the trailer.
This means that you need to have a good connection from the negative battery supply of the truck, to the truck frame. Then, at the rear of the vehicle, you need to have a good electrical connection of the white ground wire to the truck frame.

At the trailer side, if you use the trailer frame, you need to have a good connection of the white wire to the trailer frame. Then, at the bulb side, you need to have a good connection of the ground side of the bulb to the trailer frame.

As one of the posts suggested, because of the frequent imersion of the trailer frame in water, it is often a good idea to carry a separate white ground wire, all the way from the front of the trailer to each trailer bulb, to insure having a good ground at each trailer bulb location.

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When checking for grounds, if you find rusted fastners - screws bolts, etc. it is likely a good idea to remove the fastners from the frame. Then, use a grinder to grind away any surface rust on the frame. Cut off the ring fastner on the white wire, and recrimp a toothed ring on the white wire. Reattach the white wire to the frame connection - whether on the tow vehicle or trailer, and recoat the area with grease on both sides of the frame member. The thick sticky grease will retard the formation of rust on the newly cleaned connection.

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Don't overlook the possiblity that if your trailer has had frequent use, or is old, that there may be an internal break in one or more of the trailer wire pigtails.
I recently had a similar problem; even after replacing all of the trailer lights with new LED lights. I finally traced the problem to a broken white wire inside the insulation as the wiring pigtail was connected to the trailers internal wiring harness.

The cure was simple. Chop off the trailer pigtail, pull out a bit more of the trailer wiring harness, and reattach a new trailer pigtail. Then, resecure the pigtail to the trailer to prevent pigtail movement and internal breakage. Over time, the pigtail moves around a lot, and wires will flex and eventually break down over long periods of time.

Take care
REW

[wallytap]

Thanks to all! Finally found the culprit: The receptacle on the truck was taken apart and found to have corrosion on the ground lead pin. This of course is after re-grounding tail lights/trailer harness...it was the truck! DUH me.Thanks Boys, got er done.

[Hot Runr Guy]

Consider yourself lucky. You got off a lot cheaper than most guys we give advice to!

HRG