Trailer turn signals not working only when braking?

[thegipper]

My boat trailer turns signals work but when I hit the brakes, they stop flashing? Normally the one side that has the turn signal on flashes and the other just brightens up when you push on the brakes.

Otherwise, all of the lights and everything work fine.

Any idea why this is happening?

 

[flyingscott]

Clean the ground wires

 

[Maclin]

What do you tow with?

 

[ahicks]

Do you have the running lights working?

 

[211libwtfo]

Clean the hitch ball, receiver trailer ball socket. I re did EVERYTHING on my Expedition nothing worked my buddy says try this bam everything worked immediately I had a wire brush that chucked in my cordless drill.

 

[fhhuber]

Double check the wiring... might have the trailer wires crossed.

And yes, it may be improperly grounded. Make sure you have a good ground WIRE between tow vehicle and trailer. You CAN get the ground via the ball in testing... but that is not reliable ever on the road.

 

[T_Herrod]

Check the ground. Always run a wire. Never ground thru the ball.

 

[Maclin]

What vehicle are you towing with? Did it come with towing package pre-wired? Flat-4 or 5 or 7 pin round? Is the trailer new to the vehicle?

 

[roscoe]

going with Maclin on this.

a bad converter on the tow vehicle.

grounds can do funny things, but if you have working tail/running lights and brake lights, it should be good for the signals.

 

[Blind Date]

My boat trailer turns signals work but when I hit the brakes, they stop flashing?

Considering the brake lights and turn signals are the same filament in the bulb I'd say this is perfectly normal.

 

[roscoe]

Considering the brake lights and turn signals are the same filament in the bulb I'd say this is perfectly normal.

No, the turn signal should still continue flashing when brakes are applied.
How else would anyone know you are intending to turn when sitting at a stop sign, or when braking before you turn?

 

[ahicks]

thegipper seems to have left the building...

 

[GA_Boater]

Clean the hitch ball, receiver trailer ball socket. I re did EVERYTHING on my Expedition nothing worked my buddy says try this bam everything worked immediately I had a wire brush that chucked in my cordless drill.

And your trailer lights flicker all the time, if they are working. Use the white ground wire which bypasses the ball and coupler grounding.

 

[Bayou Dave]

My boat trailer turns signals work but when I hit the brakes, they stop flashing? Normally the one side that has the turn signal on flashes and the other just brightens up when you push on the brakes.

Otherwise, all of the lights and everything work fine.

Any idea why this is happening?

Seems normal to me.

 

[flyingscott]

Seems normal to me.

How is that normal? The blinker always overrides the brake light when turning.

 

[Bayou Dave]

Unless I misread the post it seems like one side is blinking/flashing when he turns on the turn signal and the other side goes brighter when he depresses the brake at the same time. How is that not working properly?

 

[72fj40]

Unless I misread the post it seems like one side is blinking/flashing when he turns on the turn signal and the other side goes brighter when he depresses the brake at the same time. How is that not working properly?

He states the light quits blinking when he hits the brake. My guess is, he has separate turn and brake lights on the tow vehicle and the trailer has a combination turn/stop/running light. If that's the case he would need to get a conversion module.

 

[Bayou Dave]

He states the light quits blinking when he hits the brake. My guess is, he has separate turn and brake lights on the tow vehicle and the trailer has a combination turn/stop/running light. If that's the case he would need to get a conversion module.

OK... I have my stupid hat on today. :embarassed: I see your point.

 

[MH Hawker]

if cleaning the ball fixed it then the trailer has a bad ground wire

 

[thegipper]

So sorry for the delay guys! I got side tracked and totally forgot to check back.

Let me be clear of the problem.

Running lights work perfect, no issues
Brake lights work perfect, no issues
Turn signals work, but the light stops flashing if I put my foot on the brake (example: put left turn signal on, left trailer light flashes. If I put my foot on the brake, the light stops flashing and just gets brighter like the right light)
Turn signals work fine as long as my foot is off the brake

Vehicle is a 97 4runner that I believe was prewired, flat 4 connector
The ground for the trailer wires does ground to the trailer