trailer lights

[scott craven]

Broke the wiring harness (4 wire) and had to replace the male end
(from the truck).
I get running lights, but no turn signal ???
all wires are color coded, white,brown,yellow,green and joined
accordingly.
Any idea what may be wrong ?

 

[Gomphus]

9 time out of 10 the problem is the ground. Running lights can operate by having a back feed from the turn signal lights.

The fact that neither of the turn signals work indicates that either the ground is not good or that two wires are not connected. If your wire colours are correct, the following are the colour codes;

White - ground
Brown - Tail lights
Yellow - Left turn
Green - right turn

If you have a voltmeter check the voltage at the connector between the different sockets and the ground socket. The turn signals will be intermittent due to flashing but you will get a reading.

If you don't have a meter, get a piece of wire and connect it from a ground on the vehicle to the trailer and see if all lights will work. If they do work on the ground wire.

Another symptom of bad ground is the running lights will come on, but when you turn on the turn signal the running light will flash and the turn signal will not.

Good luck and lots of patience!

 

[GLG]

RSC check for power on the connector. If none at the truck side check your fuses. If it’s a Ford you might have fuses in two locations. Mine has fuse inside under the steering wheel and also under the hood. Could be when the wire broke you may have had a short and blew a fuse. GLG

 

[scott craven]

I reattached the ground to the trailer
no luck.
will bum a voltmeter and try that.

Thanks a lot for the info !

 

[flytyer]

RS
When you get the meter, check continuity first from the ground pin on the new plug to you truck frame, if that is ok, you may want to check all the butt connectors that you used to make sure that wire was crimped inside.( If you did it right, you would have soldered and and heat shrink the wire)

If you can have someone , or use a piece of wood against the brake pedal to see if you get a signal down both turn signal wires. Last thing----or mayby even first--- check the bulbs for blown filaments.

[8D][8D]

 

[danthewire]

Scott,is it the flat rectangular type connector that you have?If so look and see if they are contacting,make sure that the male end is going all the way into the female end.There are some plugs on the market that will fit together but do not make full contact,i've fixed a couple for people in the last year or so.I change them in pairs,Also the female plug should be on the supply voltage side to avoid exposed pins from shorting out.Keep us posted as to what the problem turns out to be.DAN

 

[scott craven]

Thanks Dan, i will try that also..
i noticed the fit was very snug, and you had to push real hard
to get the 2 pieces coupled.
Maybe i will ream out the female end's a bit to make the fit better

 

[HALILLAMA]

Use a 12 volt test light. It is the quickest way to check it all.
Attach the ground clip to the exposed(grd) pin on the female truck connector and turn on the tail lights and probe the brown wire or socket(it should light the test light). Once you've confirmed that you have a good ground and the test light works, then turn on a turn signal and poke the wire,follow along it up to where the connection was made into the truck harness looking for the light to flash. What make/year of truck? Usually if the trucks taillights are working the fuse is ok.(unless it's a newer ride w/trailer tow pkg.) If that's the case there is a fuse box under the hood. Read your manual and the label under the fuse lid. The SAE colors for the 4 wire connector are, Brown- tail, yellow-left turn, green-right turn, white-grnd. Good Luck [8D], remember Patience is good!

 

[Gomphus]

In general the trailer lights are tapped in after the fuse in parallel with the lights on the vehicle. If the turn signal on the vehicle works, usually the lights to the trailer should work. The exception will be if the lights are factory wired. Then there may be a fuse.

The fact that both turn lights are not working is the clue that points to a ground.

I am assuming that you do not have one of those vehicles that requires the converter box because the vehicle has one light for the brake and another for the turn signals (usually amber turn signals). That is another level of complexity.

When you step on the brake and turn on the brake lights, do the running lights go out? If they do that is a ground problem for sure.

The 12 V light used as a probe is a good suggestion. Be sure to put the leads to the correct points on the connector. Start at the vehicle and make sure that you have the voltages there correct. Then go to the trailer. The problem could even be that both bulbs are not making contact at the socket for the turn filament.

Start at the front and work your way to the back of thetrailer. Trailer lighting is one of those things put on earth to cause aggravation.

 

[scott craven]

quote:Originally posted by HALILLAMA

Use a 12 volt test light. It is the quickest way to check it all.
Attach the ground clip to the exposed(grd) pin on the female truck connector and turn on the tail lights and probe the brown wire or socket(it should light the test light). Once you've confirmed that you have a good ground and the test light works, then turn on a turn signal and poke the wire,follow along it up to where the connection was made into the truck harness looking for the light to flash. What make/year of truck? Usually if the trucks taillights are working the fuse is ok.(unless it's a newer ride w/trailer tow pkg.) If that's the case there is a fuse box under the hood. Read your manual and the label under the fuse lid. The SAE colors for the 4 wire connector are, Brown- tail, yellow-left turn, green-right turn, white-grnd. Good Luck [8D], remember Patience is good!

OK,first it's a 1991 Toyota 4x4 ...
I used a tester on the brown wire both at the truck and the trailer
connections and they both lit up. so there's power there.
still no signal or brake lights ??

By the way, thanks to everyone for your advice
a little frustrating, but eventually will win this one

 

[Gomphus]

quote:I used a tester on the brown wire both at the truck and the trailer
connections and they both lit up

Use the tester at the truck. Put one lead to the ground pin (the one that is open) and the other lead into the yellow and then the green. Do either of them light up when the brake light is on or the turn signal is flashing?

Use the ground pin on the trailer connector at the truck rather than the frame of the truck.

Does the Toyota have a separate bulbs for the brake signal and for the turn signal? If they do you need one of those flash adapters that combine the brake and turn signals to the trailer.

 

[HALILLAMA]

I agree a Toyota p/u has seperate brake bulbs and turn signal bulbs so.... follow the wiring from the 4 wire plug up to the body and there will be a little box w/more wires goin in than coming out...test the wires for turn lights on the truck wiring side of the box and for brake light wire going into the box. If power is there and not coming out, it more than likely needs a new taillight convertor. These are available in any auto-parts store (can-tire etc).
To hook it up just change 1 wire at a time and use the wiring diag provided. Good Luck Retest everything at 4 wire plug, then plug into trailer and retest again!

 

[Cedarstrip]

IMHO
If feasable, save yourself all the trouble, cause its going to happen again, and build yourself a light-bar!
Going on to 7 years now with this one of trouble-free use. Haven't even changed a bulb yet.

 

[adrianna3]

I agree with Cedarstrip. I spent $200 on all new lights, wire and materials, then spent two days rewiring my whole trailer from stem to stern. I was extra careful to seal all connections with silicone and liquid electrical tape. Then I tucked everything up out of the way to keep it dry. Two months later one whole side crapped out.
I went to Can Tire and got a $40 light set and an extension cord and built a light bar on a 2x4. Works great. No problems ever again.

 

[scott craven]

After several hours, and lot's of foul language my buddy and i got the lights working. while testing i had left bare wires dangling
too close to my metal bumper, thereby causing numerous short's.
Several fuses, and a few bulbs later it was beer time !
Thanks to all !