Trailer Lights Again

I just got done cleaning and repairing trailer to truck wiring. All the lights work great except when the flashers are on they are not in synic. Any ideas?

Thanks J

My trailer lights are not in sinc either but as long as they work there should be no problems. The reason for the off timing is most likely due to the length of wire running to the lights just remember that that signal takes a little bit to get there.

Not sure what you mean by not in sync…..So if one of the turn signals is on, it doesn’t light up at the same time as the light on the truck? Did it work this way before or is this something new? It occurs to me that a factory wiring job might do that on purpose. The current draw would be less if the turn signal lights took turns lighting up.

Quote:

---

The reason for the off timing is most likely due to the length of wire running to the lights just remember that that signal takes a little bit to get there.

---

Not quite. The when voltage is applied to the trailer wiring harness it will travel from the connector back to the lights at 95% of the speed of light. You’d never be able to see it happen

Rootski

Rootski, what I mean by in sync, is the tail lights on the trailer don’t blink at the same speed, it looks like a cop car alternating back and forth

It is a bad ground… my trailer lights did the same thing so I actually hard wired a ground into both sides of my trailer directly at the tail lights on BOTH sides… (just doing one side will leave it the way it is) problem solved… good luck

Quote:

---

It is a bad ground… my trailer lights did the same thing so I actually hard wired a ground into both sides of my trailer directly at the tail lights on BOTH sides… (just doing one side will leave it the way it is) problem solved… good luck

---

x2, what he said. Run a set of ground wires from the 4-flat plug all the way back to each taillight.
HRG

You may want to replace the turn signal flasher? by replacing the original flasher to eliminate the rapid flashing of turn signals due to increased amperage draw from the trailer lights? I think the part# is 51206 or there is a thermal flasher tf536/552.

If it is a truck, it should have a Heavy Duty flasher already. I vote bad ground.

big G

I would just buy a new boat.

I think you got one bad eye, one good eye!

Let’s not be picking on the blind! I lost my left eye when I was 16 due to being shot. But yeah it sounds like a ground issue. I had similar issues and found out that I was simply not getting good contact with my ground. Took my grinder to the metal and it was good to go.

I would venture to say….80% of trailer light issues are caused by a bad ground.

If it would convince the better half that I need a new boat…..I like Targa’s idea

Quote:

---

It is a bad ground… my trailer lights did the same thing so I actually hard wired a ground into both sides of my trailer directly at the tail lights on BOTH sides… (just doing one side will leave it the way it is) problem solved… good luck

---

What if you have fender lights as well ?

Heres another hint guys. When using the clamp on terminals to the end of the wires, strip back a little insulation and solder all the conections using flux and any solder, I use plumbing solder because I’ve got some, use shrink wrap on the soldered connection where your splicing wires. Drill a hole in the trailer frame by each set of lights and use self taping screws to run through the wire terminals or ends. Also ground the trailer to the truck through the wireing harness, a ground wire on each side of the hitch ball. Drilling a hole on the truck side of the harness and grounding that and you’ll rarely have a problem. I think I’ve got about 10 years on mine and their still running.

Quote:

---

I would venture to say….80% of trailer light issues are caused by a bad ground.

If it would convince the better half that I need a new boat…..I like Targa’s idea

---

I think maybe closer to 95% of lighting problems is due to a bad ground. About every other year I disconnect, clean, and reconnect my ground wires just to be safe.

Quote:

---

If it is a truck, it should have a Heavy Duty flasher already. I vote bad ground.

big G

---

I’m with you fellas

Ground vote for this guy.

Some trucks do have a seperate emergency flasher in the towing harness that will flash at a different rate. I also had a Isuzu work truck that had a flasher for right and a flasher for left, that one looked like wig wags on a cop car only reeeeally slow.