Lights

[madmark]

I have replaced the old 4 wire plugs on my trailer and Bronco. I have tail lights and turn signals and brake lights. Here is the problem. When the trailer lights are on and I hit the brake, all of the tail lights go off on the trailer and i have no brake lights on the trailer . I have ran new ground wires from the car to the trailer and it is grounded to the trailer. <br />Any advice is appreciated.

 

[Bass Runner]

Re: Lights

Sounds like you are loosing your ground somewhere, try putting ground wires on the taillight housings, check your wiring, the ground is broken somewhere.

 

[voxmorgan]

Re: Lights

I agree try and run the car ground right back to the taillights. This is a typical sign of poor grounding.

 

[jtexas]

Re: Lights

You mean the taillights & turn signals on the trailer work until you apply the brakes, then come back on when you let up?<br /><br />If your trailer is anything like mine, you might have to look around for a rust-free bolt to connect the ground wire to. Strip enough insulation to wrap it all the way around, and make sure it's tight. Running ground wires all the way to the lights like the other guys said is more reliable.<br /><br />Also, it's a good idea to test it with the trailer unhitched. The hitch/ball connection can fool you by intermittently providing a path to ground.

 

[cp]

Re: Lights

IMHO it's not a poor ground. Here's why: You say the lights are on until you hit the brakes (and come back on when you take your foot off the pedal?), and you've run a separate ground wire to the trailer. It doesn't make sense that the lights would be on until you hit the brakes if it were just a poor ground; the ground pin in the connector doesn't change when you hit the brakes. More likely you've miswired the new connector(s), or worse have a failure in the adapter unit between your Bronco and the trailer such that when the relay cycles you're completely disconnecting the ground. Another thought - if you've replaced the bulbs in your lights, the kind with dual filaments, you might check to see that you've got them oriented correctly (disregard this if you have only single filament bulbs). Good luck, let us know how this turns out.

 

[poolshark38759]

Re: Lights

i have had similar probs with my Bronco and various trailers... prob was 9 outta 10 times GROUND. i fixed it by cleaning the ground wire and the area where it attached to the frames... and my lighs work now... all of them like they are supposed to work... <br /><br />PS...my hitch will not ground because of the thin rubber around it and the hitch pin to stop rattles and its a cushioned hitch from convert-a-ball....

 

[jtexas]

Re: Lights

Can't argue with your logic, pchonda, but I did experience a similar situation where I had turn signals but no brakelights unless the running lights were on, in which case I had taillights only. Turned out the ground was ok for some of the lights but too weak (in my case due to rust) to power them all.

 

[datawire]

Re: Lights

What does it do when you turn on the emergency flashers? This should be the same as hitting your brakes - but uses a different flasher module than your turn signals. I'm betting it's the ground too!

 

[Crabapple Cove]

Re: Lights

Experenced problems on tilt trailer,new lights and new wiring but still no ground! Spent next 2 hours trying to trace problem, found tilt bolt rusty, broke open 3-4 times, ground solved. Wal-Mart has tester for $3 to check power (at reciver) before starting on trailer, this small plug-in LED tester is money well spent!<br />

 

[djvan]

Re: Lights

It's been my experience that 9 out 10 times dim lights or lights that go out when something else is turned on is a ground problem. When re wiring run multiple grounds to good clean connections.(multiple meaning one at each light and try to also run a ground through the harness to each light.)<br /><br />HTH's<br /><br />DougV>

 

[rwise]

Re: Lights

Rivershier<br />Did you get it fixed? If so what did you find?

 

[Richok]

Re: Lights

I agree with most of these guys it probably ground. I would test my plug out of the vehicle to double check. <br /><br />I don't know what type 4 wire plug you put back, but I ran into a strange thing like this once with my 6 way. I had one strand of brake light wire touching another strand inside the plug and no lights when I hit the brake.

 

[Boatist]

Re: Lights

RiverSkier and Pchonda<br />I also think it is a ground but kinda of unusal for both lights to fail. <br />1: Where is the ground wire on your lights?? <br />2: Does it have a ground wire coming out of the light or does it just use the light mounting stud??<br />3: If you turn your lights off and turn on the flashers do the lights flash dim??<br /><br />I do not belive a Bronco requires a adapter as I belive Bronco uses same light for turn signal as for the brake light.<br />Here is why it makes since to be a bad ground to the light.<br />With the lights on +12 volts if feed back to the trailer and to the tail light filaments. Under normal conditions the other side of the filiaments is grounded to the trailer frame and the light comes on. If the light is not grounded then the +12 volts flows thru the filaments and the base of the lamp also messures 12 volts. Since the base of the lamp in a dual filament bulb is also tied to the brake light filament voltage flow thru the brake lamp filament and back to the truck on the 12 volt brake line. Since the 12 volt brake line also go to the truck brake light current flows thru the truck brake light to ground and the trailer tail light turns on. The brake light normaly does not turn on as it is a much bigger filament and requires more current than can flow thru the trailers tail light to turn on.<br /><br />Now when you step on the brake with the lights on the light will go out because you how have 12 volts on both side of the lamp and no path to ground.<br /><br />If you have a Volt meter, 12 volt test light, or a long ground wire easy to check. The outer base of a dual filament bulb should never be +12 volts. So turn the light on and take the meter or test lamp and touch the outer part of the base with the + meter lead, connect the other meter lead to ground. If the meter reads voltage or your test lamp turn on then no ground on the base. If you touch a good ground wire to the outer part of the bulb with lights and flasher on it should work right.<br /><br />If your have a newer style bulbs where do not have a outer metal base then look for voltage on the lights ground post or ground wire. <br /><br />To test must be sure meter or test light ground wire or gound wire have a good ground all the way to the main frame or truck frame. <br /><br />Hope this makes since to you.

 

[cp]

Re: Lights

Boatist - What you say makes perfectly good electrical sense and I'm inclined to agree.<br /><br />Just so folks understand why I didn't think a bad ground was the problem, please let me elaborate:<br /><br />One of the reasons I thought riverskier's problem might not be a ground is because he said he'd run separate ground wires from the car to the trailer:<br />

I have ran new ground wires from the car to the trailer and it is grounded to the trailer.

<br />That would mean that every one of his lights individually would have to have a bad ground to the trailer and that seemed to be asking for too much coincidence. And oh-by-the-way, all these lights would have to coincidentally develop bad grounds coincidentally at the same time that he happened to replace the 4-wire plugs (I presumed his lights were working before that). Hope you can see why I thought that was just way too much coincidence when the only thing that really changed was the installation of the new plugs/connectors.<br /><br />But I'm intimately familiar with Murphy's Law , so we'll just have to hope he finds the problem and posts his findings so we can all learn. Thanks for clearly explaining the electrical circuit .<br /><br />p.s. On my submersible trailer lights the bulbs are sealed inside the plastic assembly so there's no access to the bulb bases. On non-sealed lights, I'd be even more inclined to agree that corrosion between the bulb and socket would cause a poor ground.

 

[Richok]

Re: Lights

Boatist brought something to mind. I have a chevy pickup that uses the adapter. It has a reverse ground in it. It can mess you up big time. The white wire coming out of the plug actually goes to reverse. I remember I had some type of problem like this when my fatherinlaw and I hooked it up. I had to go around the plug to get a good ground. I know you have already run ground wires but it may be something else in the way the adapter is wired. Just a thought.

 

[Boatist]

Re: Lights

Pchonda<br />You sure could be right as well. Since he posted June 7 and has not been back we are all probably wasteing our time anyway. With a meter or test light it is at best a 5 minute problem to find the cause. <br />Good post.

 

[jtexas]

Re: Lights

Originally posted by Boatist:<br /> ... Since he posted June 7 and has not been back we are all probably wasteing our time anyway. With a meter or test light it is at best a 5 minute problem to find the cause. <br />Good post.

Probably a moot point as to the original question, but still worth reading, IMO, just to gain a little better understanding. Thanks for taking the time.

 

[madmark]

Re: Lights

Sorry for not responding earlier. Thanks for all of your input and replies. It was a ground problem. Had to run a wire to each light to make it work. Bigger problems now. Rod bearing siezed up in motor, in process of doing overhaul.

 

[Boatist]

Re: Lights

Riverskier<br />Thanks for coming back to lets us know the Fix. <br />Good luck with your motor.