I have a small utility trailer that when the parking lights are on the parking lights blink with the turn signals and the 4 ways..........what is going on???

Much like Les, I'd say its wired wrong.

You said it all when you said "trailer lights". Trailer lights were the Egyptian plague that accidentally got left out when the ancient Biblical texts were first translated. In an attempt to sound like I really know what I'm talking about, I'm going to throw in the always popular, "You've got a bad ground." That isn't going to help any, but there it is anyway. Best (and good luck), John

Grounded through the ball? Most trailer lighting problems I run into are from a poor ground.

No chance. This is just a recent thing..........they worked fine for a long time!!!

Lost ground somewhere.

A poor ground can cause some really strange problems. Grounding through the hitch ball instead of a wire is commonly the problem.

By parking lights, do you mean tail lights? Do you have the common 1157 bulbs with 2 filaments for tail & signal light or do you have separate bulbs for each? When the signal lights are on, does the tail light flash at all, even dimly?

Trailer lights? You're really trying to prove to the locals that you ain't from Georgia...

If it's not a ground it might be a short. That ought to help, too.

Wish I could help....but I have a kitchen sink that won't drain, and I just climbed outta a bath [bleep] tub of dishes, literally.

Electrical stuff can be crazy.

Best of luck.

As long as they look like this he should be okay...

It's almost certain to be the ground. A good rule-of-thumb is on trailer wiring, it's always the ground.

Good advice 99% of all electrical problems are ground related.

Pat

Thanks, but not due to any special intelligence on my part, just the school of hard knocks, where this is concerned. heheh

First thing to do when wiring a trailer is to hook up a GOOD ground.

Turn headlights on; hook up trailer tail lights.

Turn left turn signal on; hook up trailer L.T.

Then right turn.

That way, you don't have to worry about stop lights as they work through the turn signals.

My boat trailer was grounded through the ball and the tongue is a slip fit into a tube and pinned in place. A few years ago the lights had me running in circles for a couple of hours until I realized that the tongue was isolated from the frame by crud/rust in the tube. Electrically bonded the tongue to the trailer frame, grounded through the plug from the truck and no more problems.

This coming from one who moved from Alaska to Louisianna........and in the Coast Guard yet........surely you jest!!!

Nope, but one from the south that understands trailer lights ain't need down here.

Poor ground. Run a ground wire from the trailer to the vehicle!!!!

99.9999% bad ground. Each light has it's own ground, and trailer and vehicle have a main ground. First check trailer main ground.

Agreed that ground is most likely. I had a problem with a trailer last year that was hard to find. Wiring harness was run over the axle & an overload caused the harness to be crushed & short out. It was in a tough place to see & I felt it by acccident.

Check to see if there's a possible "Pinch point" where the harness may run & cause damage from hitting a large bump and/or overload. Longshot, but easy to look for, if grounding is not the issue.

Most likely the ground--strange things can happen with a weak ground......




Casey

Up here in the land of salt encrusted winters,I usually have to replace lights and wires every few years.Next time ,Im going with the way more expensive LED lights,problems solved.

I live in the land of snow and road salt too.

I use to have to replace my trailer light connectors every year.
Now I slobber dielectric silicone grease all over the connectors.

The ones on my Ford Truck are now 7 years old, and still work perfect !!!

Try it, it really works great on ANY electrical connector to keep moisture and corrosion at bay.

I get mine at NAPA...

Patrick F. MacManus as a funny story about hooking up trailer lights if I recall correctly... Tried to find it on the 'net but could not.

John

I know the story you're talking about. Its a real side splitter.

My experience with trailer lights is to get someone who knows what he is doing to fix them instead of trying to do it yourself. They still won't work right, but at least you'll have someone else to blame rather than yourself.

I think one line was something like:

"There is, of course, a finite number of wrong combinations of wire connections/colors. That number is 24,458,441." (or some other huge number).

I also have a dim recollection of him explaining why hooking up trailer lights is the leading cause of divorce in America...

Anyway, definitely a funny story and one I wish I could share here, but somebody borrowed all of my Patrick F. MacManus books! Wish I could recall who!

John

After installing LED's on my trailer, I'll never go back. They're bright and water tight. I also run all the wires through conduits. It's more work but not all that expensive and it sure helps protect them. You can also use some kind of rubber or plastic tubing around them, anything to protect them from the road crud.

Didn't hook the trailer up to a different vehicle did you? Some trucks/cars use tail light configurations that require an adapter box to work with trailer lights. Another tow vehicle could be wired wrong. If attached to a vehicle that worked before I'll add my voice to the choir saying bad ground. Could be bad on the trailer or tow vehicle. Usually gets corroded where screwed to the frame, corroded at a poorly crimped wire terminal or a corroded multi pin connector. Also check to be sure you don't have an adapter box on the tow rig that has gone bad. Hook a battery jumper cable from the frame of your truck to the frame of your trailer (make sure you have good contact thru the paint) and see if the problem goes away.
If you were a real Southern Redneck you wouldn't worry about the lights but if a "Civilized Redneck" you'll run it with the jumper cable in place.

The McManus story is called "Trailer Trials" and is in his book "The Grasshopper Trap". One of his funniest stories!

Like the others said, it's almost certainly a bad ground. Most small utility trailers are built by local welders in their small shops. They're good at welding but bad at wiring. Most of them will just throw the wiring together and won't even hook up the ground wire, relying on the frame of the trailer to provide the ground return to the truck through the hitch ball. Problem is that this only works under perfect conditions, it usually provides a really crappy ground and the lights do real funny stuff like all the lights blinking when you put on the left turn signal, etc.

Look at BGunn's schematic above and see where the trailer connector says "ground to trailer (white wire)". Find that wire coming out of your trailer connector and I'll bet it's not even hooked up, or if it is then it's all corroded. If it is hooked up then take it loose and use some sandpaper/wire brush to clean it real good. If it isn't hooked up then crimp a eyelet onto it and find or drill a hole on your trailer tongue, clean it real good with sandpaper, and screw the wire to the frame real good. I'll bet that solves your problem.

Also check to see if chipmunks, mice, or other critters have eaten the wiring anywhere along the line.

Aqualung