Trailer light question?

[charliep]

Hi all,

I just picked up a new to me princecraft stafish 15 sitting on a 2003 ezloader trailer. I had a hitch on my Jeep from my last boat. I hooked up the trailer - trailer and lights look new - and the trailer lights didn't work. I assumed it was on the Jeep end of the wiring as it has been a few years since being used. I purchased one of the testers that plug into the 4 pin receiver on the car and everything worked out. I looked at the trailer wiring and all seemed to be in order. Other posts I have read stress looking for ground wires. I have not seen anything amiss.

Is there something else I should be looking for? Any insight is appreciated.

Thanks,

Charlie

 

[Texasmark]

Re: Trailer light question?

Some trailer wiring packages rely upon ground being supplied through the hitch. If the hitch connection is rusted it may not work. A voltmeter would help in solving your problem.

Mark

 

[Gary H NC]

Re: Trailer light question?

The white wire is the ground...be sure it is connected to the trailer frame and that connection is clean.

Here is some great diagrams on the 4 pin and other type trailer wiring..
http://www.etrailer.com/faq-wiring.aspx

 

[charliep]

Re: Trailer light question?

Mark, Thanks for such a prompt response. I plugged in the tester and said all was well. Are you saying there should also be a ground on the car side?

thanks,

charlie

 

[JimS123]

Re: Trailer light question?

Mark, Thanks for such a prompt response. I plugged in the tester and said all was well. Are you saying there should also be a ground on the car side?

thanks,

charlie

There needs to be a ground on BOTH sides.

 

[charliep]

Re: Trailer light question?

Thanks guys. I will check it out after work tomorrow. I know the trailer has a clean ground near the coupler. I cleaned the 4 pin connector on my car, but assumes the ground was part of that. I will look to see if there is a ground there.

Thanks again,

Charlie

 

[TerryMSU]

Re: Trailer light question?

There are 4 pins on the connector. Three look identical, the other is the oposite gender. That opposite gender pin supplies the ground connection on both ends. If your tester shows good, then you do have some sort of ground connection thru the vehicle. The question is, "how good is the connection?" I would look at the bulbs and sockets on the trailer. You can also supply 12 volts directly to the trailer as a test. As long as you do not have any LED lighting on the trailer, the risk is minimal. Connect the negative of the 12 volts to the ground pin on the connector and then connect the positive to each of the other pins, one at a time. If the lamps all light then the problem is on the vehicle end. If none of them light, your most probable issue is with the ground on the connector. In fact, as I think about your problem, you may have a ground at the tongue that does not make it all the way back to the actual lamps on the trailer.

TerryMSU

 

[charliep]

Re: Trailer light question?

Terry,

Thanks for the step by step process. I am an electrical newbie and I am definitely experiencing a learning curve. You are correct. The white ground wire on the trailer end connects to the coupler. So the green/brown from the connection travels the length of the trailer as does the yellow/brown. The white ground from the pin is attached directly behind the coupler and the connection looks clean. There is no ground running to or from the lights themselves. I was able to get the lights on tonight, but neither blinker worked nor did the brake lights. I thought about replacing the 4 pin connector on both the vehicle and trailer side, but wanted to have an idea that was the problem and not just pulling straws. The connector on the trailer worked on the previous owner's rig, but I know I am getting juice from my vehicle. One thing is that the pins on the trailer side are not equal length as they seem worn down a bit. Now, retrospectively I should have mentioned this, but since I knew they worked on the previous rig, I let it go. Should I just replace it and go from there?

Your patience and input is really appreciated.

Charlie

 

[lckstckn2smknbrls]

Re: Trailer light question?

Try the trailer on a different car/truck. If they work then you know your car/truck has a problem.

 

[charliep]

Re: Trailer light question?

Good point. I was actually going to try my vehicle with another trailer in the neighborhood. I am getting ready to rip things out and start over.

 

[rosser1]

Re: Trailer light question?

get a battery charger and hook it up to your pins on trailer side of wiring on pin at a time red to each pin on trailer and groung to ground on trailer wiring. it it all works then try vechile agian. if not one pin will be right side and other is left brake and turn signals. that will only work if ground is good, if it does you have a ground problem

 

[kenmyfam]

Re: Trailer light question?

The 3 biggest issues found with trailer wiring are as follows.

#1. Bad Ground
#2. Bad Ground
#3. Bad Ground

 

[kenmyfam]

Re: Trailer light question?

This may help you with the wiring.

 

[charliep]

Re: Trailer light question?

Ken and Rosser,

Thanks. I will try the charger and revisit the ground issue. Is it safe to assume that because the vehicle side has juice according to the tester that the ground is solid there? I see the white wire on the vehicle side incorporated into the pins, but is there a usual place for it to be grounded? Man, I swear I am not dumb, but trying to figure this out makes me feel like an idiot.

Thanks,

Charlie

 

[Home Cookin']

Re: Trailer light question?

those testers can fool you--I have one. Everything is perfect except the trailer won't agree. You can even have a problem at the vehicle end that the tester does not show, but plugging into the light harness finds a grounded loop.
Before you rewire, if you buy a whole new harness, test it (grounded) before you install it. Be aware that if it doesn't work, it may be defective out of the box--they are cheaply made.
Clean all connections esp at the bulbs even the ones that work, esp. if the trailer has been dunked.

Here's one that took two different repair shops three days to find: on the vehicle sidem, a white wire was grounded. It was actually a powered wire for an extra brake light (like the one in the center of the rear window) and therefore was causing a looped short. it took a frustrated but determined mechanic to question the conventional process of wiring. I tell you this b/c when it comes to trailer lights, anything can happen, you don't know what incorrect wiring you inherited (even from the factory or dealer) and you never know if a ground is really a ground.

 

[JimS123]

Re: Trailer light question?

One other thought....

When you are testing the trailer to see if the lights work, be sure to connect the trailer coupler to the car's ball. That connection secures a final positive ground. I have 4 boat trailers and they all show dimming lights if the trailer is merely sitting next to the car.

 

[charliep]

Re: Trailer light question?

Thanks everyone. It poured last night so I was unable to get to work on some of the suggestions. I will try this weekend.

Charlie

 

[charliep]

Re: Trailer light question?

No work done this weekend as it feels like we are in the midst of monsoon season up here.

Charlie

 

[charliep]

Re: Trailer light question?

Hi Guys,

Sorry that it has taken so long, but I wanted to follow up. The rains stopped and I finally had some time to work on things. I cleaned the connection at the ground and still nothing. I then went to the lights themselves trying to figure out how to add a ground. I tested the connection and there was juice. Everything looked good and I was stymied. So I looked at the bulb and it looked good. I thought that maybe it didn't have a good connection. I was curious as to why the bulb was opaque and not clear. Captain stupid here should have thought to check the bulb. I broke t as I tried to remove it and it was cooked on the inside. I replaced it and guess what? It worked. I did the same with the other side.

I am embarrassed that this was the problem that I was fretting over for 2 weeks. Honestly, I deserve any ribbing as the bulbs should have been the first thing I checked. Everything looked new so I didn't think it was an issue. Lesson? Don't forget to check the obvious first.

Thanks for all of you help along the way.

Charlie

 

[lckstckn2smknbrls]

Re: Trailer light question?

Glad you got them working. I ran a ground wire from the front of the trailer to each light.