Trailer lights delay-gctid826113

[Fishtank]

Weird behavior all of a sudden with my trailer brakes. First of all the truck is a Nissan Titan. If I haven't trailered for awhile and then hook up to the trailer, it takes about a minute before the lights (brakes, turn signals, running lights) operate. Then if I turn the truck off then on again, the lights will work immediately. This is strange and it doesn't give me much confidence when I'm trailering at night! Any ideas why this could be happening? The connection is a 5-pin harness by the way.

[Solandri]

I've got one trailer light which does that. My guess is it's due to corrosion. I suspect a layer of corrosion starts building up, and initially blocks the flow of electricity. But eventually the electricity burns off the corroded layer and it's able to get through and light the light. That's my guess based on the behavior after I fixed the light. When I got the boat, the lamp was burned out with a bit of corrosion on the contacts, and the PO had left spares aboard. So i cleaned off the contacts and changed the bulb. After doing this, it lit up immediately.

When I next launched the boat, I noticed the light had filled with water (bad seal somewhere) and didn't light up. Once the water drained, it lit up immediately the first time. All subsequent uses have been like your experience. It does not light up when i first hook up the trailer. But after a few minutes of driving, it lights up (the dead bulb indicator on my truck's dash turns off, and if it's night I can see the light is on). Once it's done that, it will light up immediately when I turn the car lights off, then on. But if I let it sit a few days, or if I launch/retrieve the boat and let it sit for a few hours, there will be a delay before the light lights again..

[builderdude]

Look at the wire connections in the trailer plug, you may have a corroded negative connection there.

[oakplank]

I'm not sure if this will help in your situation or not. But, I always disconnect my light harness before lowering the trailer into the water. Although the actual connection is above the water line, the trailer lights are under the water. That way there is no electricity going to those, under water, lights.

Water and electricity don't like each other.

Take care, on and off the water

Oakplank

[Norton_Rider]

"Fishtank" post=826113 wrote:
Weird behavior all of a sudden with my trailer brakes. First of all the truck is a Nissan Titan. If I haven't trailered for awhile and then hook up to the trailer, it takes about a minute before the lights (brakes, turn signals, running lights) operate. Then if I turn the truck off then on again, the lights will work immediately. This is strange and it doesn't give me much confidence when I'm trailering at night! Any ideas why this could be happening? The connection is a 5-pin harness by the way.

This does not sound like it has anything to do with bad grounds, contacts, etc. It sounds like it is related to the electronics on the truck. I believe that Titans have separate turn signal and brake lights. In order to connect to a trailer with combined brake and turn signal lights the two signals need to be merged into one. This is done in the aftermarket with a converter box and is done by OEMs with a dedicated box or combined with the other truck electronics. A check that you could do is to wiggle the plug, and various wires to see if that that results in the lights coming on and off. If it does, you have a loose connection, probably a ground. If it doesn't, it may be the truck.

I suggest that you go to some of the Nissan truck forums (there are various) and search for, trailer lights. You may come across others that had a similar issue.

[Fishtank]

Well, sounds like I need to figure out if it's the truck or trailer. I'm going to buy a 7-pin plug tester to check the truck. If all's well then it must be a ground because it affects all lights.

[Guest]

Agreed that you should start with the tow vehicle and ensure that the socket is behaving properly. We regularly have to troubleshoot pesky trailer lights at work, and it will often be the tow vehicle that is the problem.

Not exactly sure how the trailer sockets are set up in the US, but here in Australia I regularly check the socket on the tow vehicle with either a test light or multimeter.