Trailer brake lites go out when brakes applied??

[rv8tor]

Hi all:

I have an EZ Loader trailer for my 19' boat. I just replaced the rear tail/brake light assemblies because the others wore out. They worked fine before the red plastic lens came apart. Now mind you, this is a fairly simple remove and replace operation. The wiring can only go on one way, so they are not hooked up backwards. ..at least I don't think..

I believe the grounds are hooked up right. With headlights/running lights on, the tail lights come on just fine. When a turn signal or hazards are selected, the rears blink as well except opposite to the vehicle ones. Also, they blink off instead of just increasing the brightness (second filament) with their blink. Also when brakes are applied with running lights on, the rears go out and stay out as long as brake lights are on.

Okay, I'm usually no dummy, but I'm missing something pretty elementary here, I think.

What do you all think????

 

[NYBo]

Re: Trailer brake lites go out when brakes applied??

Almost definitely a grounding problem. If need be, run a separate ground wire to each light, tied into the white wire in the trailer harness.

 

[bruceb58]

Re: Trailer brake lites go out when brakes applied??

You have a ground problem and DON'T do the seperate ground to each light. You just make everything twice as complicated when you do that.

 

[kenmyfam]

Re: Trailer brake lites go out when brakes applied??

3 main causes of trailer light issues.

1, Bad Ground
2, Bad Ground
3, Bad Ground

Simple as that.
I have found that just reefing up some of the bolts on the trailer has fixed grounding issues on EZ loaders sometimes.
Good Luck

 

[cedarjunki]

Re: Trailer brake lites go out when brakes applied??

take a little sandpaper to where the nuts tighten down.

 

[scipper77]

Re: Trailer brake lites go out when brakes applied??

I had a similar issue last year. For me it was a broken wire at the harness (under the truck). When I applied the brake the power went to the brake light instead of the running light or something like that and the lights went out (because the wire was broken).

I might be remembering my problem incorrectly, but I do remember that I wasted time chasing down grounding and bulb issues when it was the harness the whole time. Get a dc Volt meter and make sure that you are getting power first, so you can be sure that the problem is at the trailer.

 

[NelsonQ]

Re: Trailer brake lites go out when brakes applied??

I had a similar issue last year. For me it was a broken wire at the harness (under the truck). When I applied the brake the power went to the brake light instead of the running light or something like that and the lights went out (because the wire was broken).

One quick way to check that is one of these. I keep it in my toolbox as a inexpensive a quick way to eliminate any issues on the tow vehicle. Cheap and quick.

http://www.iboats.com/Seasense-Ez-T...3583101--**********.156020337--view_id.237539

 

[marcortez]

Re: Trailer brake lites go out when brakes applied??

Neat little contraption.....and at 4 bucks the price is right.

Now if they only made one for a 5 way flat plug...

 

[Rwebber77]

Re: Trailer brake lites go out when brakes applied??

Neat little contraption.....and at 4 bucks the price is right.

Now if they only made one for a 5 way flat plug...

Ah but they do! Check here.

 

[bruceb58]

Re: Trailer brake lites go out when brakes applied??

Problem with those little devices is that they won't tell you if you have a marginal ground like the case of the OP.

 

[rv8tor]

Re: Trailer brake lites go out when brakes applied??

Thanks guys. I'll check the grounds on those two lights when I get home.

Another possibility?? ..I also replaced one of the side amber position lites with a new one, and now neither it nor the amber one just forward of it (same side) will work at all. ??? .a broken wire maybe causing this failure along with the issues in the back?

 

[kenmyfam]

Re: Trailer brake lites go out when brakes applied??

Thanks guys. I'll check the grounds on those two lights when I get home.

Another possibility?? ..I also replaced one of the side amber position lites with a new one, and now neither it nor the amber one just forward of it (same side) will work at all. ??? .a broken wire maybe causing this failure along with the issues in the back?

How was it before the new light ???

 

[nlain]

Re: Trailer brake lites go out when brakes applied??

I recently changed the tail lights on my trailer, the right one has the ground out where you can see it with the light in place, the left one has the ground behind the light, I connected the wire together, the lights on the fender would not work, I then pulled the light, cut the ground wires, put a bolt in the mount bracket then attached the ground wires to the stud, now alll lights work.

 

[backyard mechanic]

Re: Trailer brake lites go out when brakes applied??

A trouble light at the rear light assembly will tell you if the wiring is right. The little filament should burn with tail lights on and the larger filament with turn/brake. I know that's a duh statement but then (with no reflection on you) how often do you see it backwards????????????????????????????

I bet your problem is ground tho. An electrical thing called equal potential causes a bulb of lessor wattage to burn opposite a larger bulb. Very common on old Chev cars with side blinker.... It's all about resistance and grounding.

 

[TahoeQ4Pilot]

Re: Trailer brake lites go out when brakes applied??

Before I even read the thread my first thought was check the ground. Do you have a multimeter? You need to have a bit of curiosity and bunch of can do attitude to find electrical problems. But like a few have already said based on your reported symptoms, likely a grounding problem.