Trailor right turn signal only not working

[PISTONESAL]

Thanks but my trailer does not have a tilt to it. I will have to measure that point. What's wierd is that this morning all was wierd. I have a good ground from truck to trailor. I cleaned the contacts on plugs then everything started to work but now the left signal stopped. When I measure I am not getting a voltage above 3-5v. At this point I am lost if it's the trailor, truck, or wiring. I'd hate to replace the convertor box and have the same issue. The universal kit I bought - will have to cut and splice to make connections any other ideas anyone? Man its very frustrating..

 

[82rude]

I had the exact same issue with my trailer and my problem was the factory wiring harness.I bought one of those wiring harnesses that plugs into the rear lights and no more problems.Drove me nuts for quite a while.Im pretty sure it was a reese kit i got from canuck tire.

 

[jimmbo]

The "3 - 5v" measurement, was that from power source to ground, or across a connection/splice?
Low voltage is usually caused by a higher than normal load and/or poor connections(corrosion, loose, internal wire breakage). Poor/cold solder joints in converter may be another spot.

 

[gm280]

With those voltage readings, it is time to start chasing down where the voltage drop-out is coming from. Start be unplugging the trailer side of the connection and read the voltage directly at the vehicle side of the connector as you turn each light on. If those readings are good, you just isolated the problem to the trailer. But if those voltage readings are not good, then you isolated the problem to the vehicle side of the connector. That is a starting point. Don't jump all over the place and confuse yourself. Trouble shooting anything means you do such in a planned fashion so the information you read leads to the problem. JMHO

 

[bruceb58]

I would actually use a test light instead of a meter at first at the trailer connection. You need a load to make sure there isn't a resistive connection somewhere,

 

[fishin98]

This post is very similar to one in a different forum.....There comes a time when to admit that events have overtaken you....Take the vehicle to a Certified Technician and have the issue resolved by someone who can trouble shoot and correct the issue.

 

[PISTONESAL]

Thanks for the replies everyone. I am an electronics technician and repair all kinds of electronics and have seen all kinds of failures so I know I can resolve this issue.. The voltages I read was at the truck from ground to the left and right turn signals. All my connections are good with no corrosion/rust/etc. But go figure, I went out this weekend and when I got back, I checked the lights and everything was working perfect? The only thing I did different was spray the truck and trailor connectors with some salt water corrosion spray (sorry forgot what its called). But I sprayed it before I had the left turn issues. Maybe the spray sitting on the contacts dissolved any corrsion that was still there(maybe?) I am off this wednesday and will check again. thanks again everyone

 

[Blind Date]

I would actually use a test light instead of a meter at first at the trailer connection. You need a load to make sure there isn't a resistive connection somewhere,

Agree. Never had a trailer lighting problem I couldn't fix with nothing more than a simple test light. As already suggested start with the tow vehicle first. If everything works there your issue is the trailer. The trailer does not need to be hooked up for your lighting to function if it is grounded correctly.

 

[bigdee]

Find a donor vehicle to plug into, preferably an American made (no converter) to rule out vehicle or trailer. If it is trailer you have a wiring/ground issue.

 

[PISTONESAL]

I will have to find someone. I did hook it up today while I was having my fence installed and everything worked except right, the fence installer had a question so I attended to him and I left the truck with right turn signal on, when I got back to trailor the right turn and everything else was working so I am really confused. It has to be a ground, right? But everything ohms out ok..

 

[gm280]

I will have to find someone. I did hook it up today while I was having my fence installed and everything worked except right, the fence installer had a question so I attended to him and I left the truck with right turn signal on, when I got back to trailor the right turn and everything else was working so I am really confused. It has to be a ground, right? But everything ohms out ok..

Things can look deceiving with an ohm meter some times. However when you load the lines with actual lights, corrosion can make the difference and not allow proper voltage through. I would absolutely go over each and every connection and redo them and clean them to bright shiny metal. I think that will solve your problems. JMHO

 

[bruceb58]

I agree, using an ohm meter to diagnose a resistive connection is pointless as the amount of resistance that can make a huge difference is less than an ohm.

Wire up a spare connector that has a ligtbulb wired up to ground and to a pin that you can plug into each oh the other connections. That way you get the trailer itself out of the equation.

 

[GA_Boater]

I'm going to throw this one out - Replace the flasher in the truck. Find an electronic flasher instead of a bi-metal clicker type.

 

[bruceb58]

I'm going to throw this one out - Replace the flasher in the truck. Find an electronic flasher instead of a bi-metal clicker type.

Left signal works fine.

 

[PISTONESAL]

I confirmed isue is on my 99 Toyota 4Runner. I replaced converter and everything works except the running lights and if I have the running lights on the trailer left nor right turn signal works anybody know what's else can be wrong?

 

[briangcc]

I'm not familiar with your model 4Runner but mine has a 7 & 4 pin plug under the driver's side rear of the vehicle. To plug my trailer into my 4Runner I have to use a 7-5 pin adapter. Is that what you are doing, using an adapter to step down from 7 pin to either 4 or 5 pin? If so, have you tried a different adapter??

Other than that, when towing with my 07/13/16 Tundra I had to run a dedicated ground from the trailer frame to the truck when I was towing my Four Winns as that trailer relied on the ground connection through the trailer ball. I put an oversized spring clamp on one end so I could disconnect the ground from the Tundra when I wasn't towing. That ground solved a myriad of issues. Might be worth looking into for your particular setup as well.

 

[PISTONESAL]

Thanks for reply. I will have to look into it. and try it. Thanks for reply. Anybody else have any thoughts?

 

[Blind Date]

Have you isolated the problem to the truck or trailer yet? Reading through the comments I cannot see where you have done that. Go to your local auto parts store, buy a test light & start with the truck. I've never needed an ohm meter to diagnose & fix trailer lighting. When I wired in a converter to my '93 Toy PU for towing, that's all I used to check and make sure it was working & wired correctly.

 

[Blind Date]

Other than that, when towing with my 07/13/16 Tundra I had to run a dedicated ground from the trailer frame to the truck when I was towing my Four Winns as that trailer relied on the ground connection through the trailer ball

That makes no sense. No trailer manufacturer that I know of wires a trailer that way for obvious reasons. They don't make a trailer wiring plug that doesn't have a ground wire. Why wouldn't you just run a ground to the trailer frame from the trailer plug?

To the OP, once your certain your truck wiring is good, check the trailer wiring harness ground at the tongue & then check the grounds for both taillight assemblies.

 

[briangcc]

That makes no sense. No trailer manufacturer that I know of wires a trailer that way for obvious reasons. They don't make a trailer wiring plug that doesn't have a ground wire. Why wouldn't you just run a ground to the trailer frame from the trailer plug?

To answer the question, which is off topic, the trailer had a 5 pin connector including the ground. However, Four Winns took that ground wire and tacked it to the trailer frame and called it a day. I never found where it was attached even after pulling the harness apart for other issues. So I added a secondary ground which took care of the issue. No muss, no fuss and only a second to connect it to the frame. Otherwise, I'd have to wait for the trailer ball to be cleaned of rust before all the lights worked properly. None of the lights had dedicated grounds to them - I know, I replaced (2) of them during my ownership.

**I don't care what the local laws said, I left my ball hitch in as I had way too many tailgaters so I figured they saw that coming their direction they'd back off - usually worked too!