Trailer lights acting up

[mmas261]

My trailer lights are connected to my Ford Explorer using a hoppy kit. All is connected correctly and grounded.When I hit my brakes the lights work but when I turn on my headlights the brake light will not work on the trailer driver side only, it goes off. The same light will not come on when I turn on headlights. Everything else works. What may be causing this one light to not work and work for braking but then go out when headlights are turned on?

 

[DJ]

Re: Trailer lights acting up

mmas261,<br /><br />The most frequent problem with trailer lights is poor grounds.<br /><br />1. Clean every wire connection you can find.<br />2. The trailer should be grounded to the tow vehicle via the white ground wire-NOT THE HITCHBALL. Make sure the white gound wire on the trailer is attached solidly to the trailer frame.<br /><br />Also, if your Explorer has the message center option (low fuel, washer fluid, etc) you are asking for trouble with that Hoppy kit.<br /><br />The message center equipped Explorers (without factory tow package) require special wiring for towing. See your Ford dealer. There was a TSB on this subject.

 

[mmas261]

Re: Trailer lights acting up

Thanks for the info DJOHNS19 I wondered if it may be the hoppy kit. I do however have the same problem when I hook up my wifes expedition which has a factory tow package and I use a 7 to 4 adapter plug. The brake lights work until I turn on the headlights and then the brake light will not function. I do however get the tail light to work with her vehicle and it goes out when brakes applied. Very strange ...... I will keep playing with it.<br /><br />Mike

 

[Ranger354]

Re: Trailer lights acting up

I would go with the bad ground. 90% of the time that is the problem. Even thought the white wires are attached properly most trailers require a rust free connection on the hitch to ball conection. I always spray the hitch and ball with some LPS.

 

[iRich]

Re: Trailer lights acting up

Are you using the right bulbs?<br /><br />Rich

 

[blifsey]

Re: Trailer lights acting up

Strange as it may seem, that sounds like a ground problem. Without a good ground, a few lights will work by themselves. But when you try several (e.g. tail lights and brake lights), there isn't enough of a ground to flow all the juice through the bulbs and back to ground. If its doing it on 2 vehicles, I would guess problem is on trailer. Check the ground wire to be sure it hasn't been partially cut. If its solid, disconnect it from where it is connected to trailer and clean the contact area. If that doesn't work, check the the lights ground to trailer frame.<br /><br />Funny story, I plugged my 7 to 4 adapter in upside one night (no, I had not been drinking)and it did wild things to my flatbed trailer lights.<br /><br />BL...

 

[TJ1962]

Re: Trailer lights acting up

I have a very similar problem and its kicking my butt. I have a dinky trailer for my 14' John boat that tow with a 1994 Ranger. I have a hoppy to convert from 7 to 4 wire. My problem is that the tail lights do not work at all. My turn and brakes work both sides as long as I do not have my taillights on. Okay for daytime fishing but I would like to do some night stuff too. Please let me know if you figure out your problem.

 

[mmas261]

Re: Trailer lights acting up

Got it fixed it was the grounds at the lights. Thanks all!!

 

[Scoop]

Re: Trailer lights acting up

I have had so many grounding problems over the years, I always run separate ground wires to each light. When I haven't, I have found that the ground will deteriorate over time and the lights will be dim. It can happen on the road and I would rather buy $10 more wire than be rear-ended.

 

[Redsfilthy]

Re: Trailer lights acting up

Take it from me, an electrician, never ground your trailer through the ball.It may work fine when you are checking your lites at a stand still, but believe me,when you turn a corner your trailer lights are blinking.Always make a solid ground on the tow vehicle. Run the ground THROUGH the plug and make a solid ground on the trailer. Bad grounds always give funny symptoms and no 2 are alike.