Electrical issue

BTPO1 wrote:

JSGlow wrote:
No to sound too naive but I did not previously know that the hitch itself was part of the circuit.

IMO the hitch could be part of the system, but it is not a very good ground. There should always be a separate ground wire (White) installed. JMO

There is a white wire. It's part of the 4 wire lead. As I recall they are black, green, yellow and white. My boat frame is enclosed tubular steel so the combined wires enter a little hole on the neck and then emerge by each taillight. An examination this morning reveals black, white and one of green/yellow at each taillight. Having had to fool with the right light last year when I had a short, my recollection is that white ground wire is attached to the trailer frame on the mounting plate behind the actual plastic turn signal fixture. That one alone had been giving me problems and a little TLC last summer cured the problem. Again, yesterday was unusual in that I initially had 100% good running lights but nothing else, followed later by running lights and 100% good left (blinker and break) but no blinker/break on right. With 45 more miles under my belt all the problems had seemingly corrected themselves 100%. That doesn't suggest a short back at either light to me and made the hitch discussion make a ton of sense. I cleaned it up further as a result.

Again, happy to get feedback from more folks who know.

Same thing happened to us. We towed a 5'er for years and every spring I had to pull off all the lens covers and tighten down all the screws in there. Trailer had an aluminum outside layer and the manufacture used it as a ground wire also.

JSGlow wrote:
No to sound too naive but I did not previously know that the hitch itself was part of the circuit.

IMO the hitch could be part of the system, but it is not a very good ground. There should always be a separate ground wire (White) installed. JMO

Thanks Roy. I think I'll buy one. Pretty sure it was the hitch. Did full test this morning here at home (trailer still fully hitched) and all was fine. I'm thinking that the friction on the way home cleaned things up enough. After disconnecting I took a light sandpaper to both the ball and trailer receiver. Both were pretty gunky, especially the trailer. No to sound too naive but I did not previously know that the hitch itself was part of the circuit.

I found having a couple of TEST ADAPTERS keeps me ahead of the game trying to figure out if it is a truck connector problem or trailer problem.

If the ADAPTERS work good plugged into the truck connector then I I know the problem is with the trailer.

A good resource for trailer wiring pointers is ETRAILER. Check out their wiring diagrams too...

I carry these two TEST ADAPTERS in my toolbox...

7-way ADAPTER Plug


4-way ADAPTER Plug


These are available from ETRAILER or AMAZON

I also always squirt some W40 into the truck connector side and work it around a few times to clean up the contact blades/pins etc before using.

Roy Ken

Corrosion will do it or the ground wire is broke and you are getting an intermittent ground through the ball. Follow the white wire to where it fastens to the rig. The white wire provides the ground.

If you had any grease ordirt in thetongue or on the ball you were not getting a good ground