no turn signals while braking?

tt600

Seaman
Joined
May 25, 2011
Messages
62
I have a flat four system wired through my existing wires. When I brake while signaling the trailer lights go solid with no flash. If I let off the brake they return to flashing. How do I get the turn signal to take priority over the brake signal?
 

oldjeep

Admiral
Joined
May 17, 2010
Messages
6,455
Re: no turn signals while braking?

Sounds like the brake and light wires are shorted together. If it worked before then check the bulb sockets or bulbs themselves
 

roscoe

Supreme Mariner
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Oct 30, 2002
Messages
21,739
Re: no turn signals while braking?

not sure what this means , "wired through my existing wires."

Anyway, the brake signal and turn signal uses the same wire and the same filament in the bulb.


You don't mention the tow vehicle.

Does it have separate turn and brake lights?
If so, you may need a converter on the vehicle.

Also, a bad, or light duty flasher unit on the vehicle, can cause this.

Try a new heavy duty flasher.
 

Al Kungel

Petty Officer 2nd Class
Joined
Jul 9, 2004
Messages
144
Re: no turn signals while braking?

I am betting it is a ground issue
 

kenmyfam

Supreme Mariner
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Re: no turn signals while braking?

I am with the bad ground thing as a starting point.
 

Thalasso

Commander
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Jan 18, 2011
Messages
2,879
Re: no turn signals while braking?

not sure what this means , "wired through my existing wires."

Anyway, the brake signal and turn signal uses the same wire and the same filament in the bulb.


You don't mention the tow vehicle.

Does it have separate turn and brake lights?
If so, you may need a converter on the vehicle.

Also, a bad, or light duty flasher unit on the vehicle, can cause this.

Try a new heavy duty flasher.

Brake light bulbs are two filiments. Do you have the bulbs in right ?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: no turn signals while braking?

The starting point is to turn on the running lights. Both tail lights should be on. Now have someone step on the brakes. The lights should both light brighter. If one is bright and one is dim then they are either wired wrong or the bulb in one light is inserted wrong. The bulbs are keyed but the sockets are so loosely made that a bulb can be forced in wrong. But I agree that a converter may be needed depending on the tow vehicle.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Re: no turn signals while braking?

if your tow vehicle has separate turn signals and brake lights, you will need a converter for the trailer.
 

kenmyfam

Supreme Mariner
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Messages
14,392
Re: no turn signals while braking?

My first question to the OP is did this set up ever work correctly or has it just happened. 2nd question is, If the answer to question 1 is yes, then has anything been changed on this set up since it worked properly originally ??
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: no turn signals while braking?

The turn signal and brake use the same fillament. Applying the brakes lights both left and right but the turn signal flasher is ahead of the brakes in the circuit so when the flasher breaks the circuit on that side it appears to flash even though the brake is applied. You've just got the wiring confused a bit. White is the common/ground, yellow and green are the brake and brown is the clearance/tail lights. Just remembe that the turn and the brakes use the same single wires. Here's a quick explanantion:

http://www.ehow.com/how_5096278_wire-trailer-lights.html
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,739
Re: no turn signals while braking?

Brake light bulbs are two filiments. Do you have the bulbs in right ?

1 bulb, 2 filaments.

One filament is for the taillight.
The other filament is for the brake light AND the turn signal.

Edit, I guess I should have look at sschefer's post before I typed.

Oh well, a little redundancy never hurt anyone.
 

tt600

Seaman
Joined
May 25, 2011
Messages
62
Re: no turn signals while braking?

Thanks for the ideas.
Let me be a little more specific about my problem. My chevy 1500(same filament for turn and brake) didn't have built in wiring for a trailer so a friend used vampire clips(his term) that just clamp onto the existing wires. All seems good with this setup except when I try to signal while braking. On either side the lights just stay solid on both truck and trailer. Inside the cab the green arrow lights up but no flash. Signaling while not braking works just fine. As to whether this problem occured from day one I can't be sure. Just noticed it recently. Is this consistent with a weak flasher? Or would a weak flasher cause problems braking or not?
 

ricohman

Lieutenant Commander
Joined
Jul 30, 2011
Messages
1,631
Re: no turn signals while braking?

Disconnect both sides and use your test light to see what you have coming out of the wires your buddy hooked up. Check the ground.

When you have figured out right and left hook one side up at a time. I would remove the bulbs and use the test light at the socket. If its dim you have problems at the socket or with the wiring in the trailer.
 

tt600

Seaman
Joined
May 25, 2011
Messages
62
Re: no turn signals while braking?

sounds like you think it is a bad ground in the trailer? Something common to both sides. I am going to go do some more tests.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: no turn signals while braking?

sounds like you think it is a bad ground in the trailer? Something common to both sides. I am going to go do some more tests.

You can get a cheap tester to plug into the vehicle end for a few $. That will isolate whether there is an issue with the tow vehicle or not. You will then know which end the issue starts at.
 

catfish58

Petty Officer 2nd Class
Joined
Jul 17, 2011
Messages
158
Re: no turn signals while braking?

I had a similar problem with mine, only just my right trailer light would not blink with the brakes on. I replaced the converter and that solved the problem.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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49,566
Re: no turn signals while braking?

I would undo what your buddy did and get a plug-n-play wiring harness. it plugs into the stock wiring harness t-connector.
 
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