Trailer Wiring question Troubleshooting

[MikeT]

I have a trailer and I am pretty bad when it comes to doing electronic things. My drivers side tail light on the trailer will illuminate with the lights on but it does not blink brightly when the signal is on. It also will not get bright when the brake lights are on. My other tail light (on the trailer) works perfectly. This is a simple tail light kit that you would get from Harbor freight or Walmart, nothing special. I have uploaded the picture of my multi meter but I am not sure how to use it to see if I have a good ground. I have heard that the ground might be the problem but I just don't know how to check it.

Can someone give me a little tutorial on how to go about getting this fixed?

Thanks!

 

[_JOE_]

Check the resistance between the bulb socket and ground. If there is rust/corrosion under the wire where it bolts to the trailer frame it will cause the symptoms you have.

 

[MikeT]

Check the resistance between the bulb socket and ground.

So I want to see a very low number, correct? A low number of ohms would be what I am looking for correct?

 

[ellandoh]

low ohms is correct, i would put one lead to the socket and one to the trailer frame to get a reading of 0 or close to 0 would be ideal

 

[_JOE_]

Right. Before you take your reading between the socket and frame touch the meter leads together and get a base reading. Most leads have an ohm or two of resistance, just subtract that reading from your total. You'll likely see over 4 or 5 ohms if your issue is in the ground circuit.

 

[MikeT]

Well, I will use this if I ever have this problem again..... I have discovered the problem and it is just plain aggravating. When I was checking the lights themselves out, I switched the bulbs between the good side and the bad side. When I put the good bulb in the bad side, I noticed that the bulb neede an extra little twist to get it to click in the cheap sockets. once it did, the bulb made good contact and viola! everything worked..

I guess it was a ground problem because the bulb just wasn't sitting in the socket correctly :bang:

 

[_JOE_]

Good deal, glad to hear it's all sorted out!