richg99
Well-known member
OK..this is going to sound whacko, but it is true.
Vehicle 2014 Toyota Sienna Van
Boat trailer. This trailer has side running lights, so I can see if the Running Lights are on or not while driving.
The RUNNING Lights ( ONLY the running lights) work intermittently.
#1. It isn't the Ground wire (all other lights flash and work)
#2. It affects only the Running Lights (Brown wire)
#3. I've had the trailer installer check things out and they couldn't come up with the answer.
#4 I've had a local auto mechanic, who is pretty sharp, check things out.
First off, I REALLY don't know if this is a new occurrence or has been going on for some time. I recently noticed it shortly after I purchased a New-to-me 2007 Lowe 1756 tinny. For the first few times that I towed the trailer, the trailer running lights worked just fine. Then, the TRAILER RUNNING LIGHTS stopped working, but the directional lights all worked and the brake lights all worked.The van's Running Lights work just fine.
After leaving it with the aforementioned mechanic, he deduced that the issue was on the VEHICLE side, not the trailer side. A voltmeter, applied to the Brown wire output showed only (.6 volts) when the outage was occurring.
There is a "black box" connected between the van's taillights and the extension that runs to the outlet connector near the hitch receiver.
I decided that I'd simply replace the wiring harness, which included the "black box" with the exact recommended one, which matched the wiring harness that we discarded. The original trailer wiring harness came with the installation of the hitch approximately two years ago.
After installation of the new wiring harness, the same issues kept occurring sporadically. The guys who put the wiring harness in said that they would replace it...but they couldn't find out what the issue really was.
As things happened, and after the hitch installer worked on the wiring harness with his 12-volt tester, the darn system worked... it worked well, for about three weeks.
However, today it has reverted back to sporadically functioning and then not functioning.
Some additional weird observations....
A. When the Running Lights are NOT working, I can, sometimes, rotate the Light Control on my van, and watch the Running Lights flash on and then off.
B. Other times, rotating the Light Control on my van, causes the Trailer Running lights to start working again and stay on.
C. Today, I noticed a new phenomenon...IF I STEP ON THE BRAKE PEDAL, and at the same time Rotate the Light Control in my van, the Trailer Running Lights come on and stay on???
Now, earlier, I said that this might have been going on for two years. The reason that I cannot verify that is that the original Trailer Harness was used on this same van, but on my other boat. That boat is now in TN. It did not have Side Running Lights, so I had no way of noticing if the Running Lights on that trailer were on when they should have been on, or not. I didn't drive that rig often in the dark, so Running Lights were not required. They may have been working, or they might not have been working.
Wheew.. Long story for such a "simple" problem. I did send a message to Curt Company a week or two ago...(The manufacturer) but never received a response.
This isn't my first rodeo with trailer lights, but it sure has me, and two mechanics stumped.
I believe that it has a lot to do with the "black box" which, as I understand it, is there to "fool" the van's lighting system from shutting off when additional trailer lights are added.
Curt's wiring harnesses even provide for an additional heavy wire to be connected directly to the van's battery so that the new lights don't overload the present van's lighting system
Has anyone else experienced anything like this?
regards, richg99
Vehicle 2014 Toyota Sienna Van
Boat trailer. This trailer has side running lights, so I can see if the Running Lights are on or not while driving.
The RUNNING Lights ( ONLY the running lights) work intermittently.
#1. It isn't the Ground wire (all other lights flash and work)
#2. It affects only the Running Lights (Brown wire)
#3. I've had the trailer installer check things out and they couldn't come up with the answer.
#4 I've had a local auto mechanic, who is pretty sharp, check things out.
First off, I REALLY don't know if this is a new occurrence or has been going on for some time. I recently noticed it shortly after I purchased a New-to-me 2007 Lowe 1756 tinny. For the first few times that I towed the trailer, the trailer running lights worked just fine. Then, the TRAILER RUNNING LIGHTS stopped working, but the directional lights all worked and the brake lights all worked.The van's Running Lights work just fine.
After leaving it with the aforementioned mechanic, he deduced that the issue was on the VEHICLE side, not the trailer side. A voltmeter, applied to the Brown wire output showed only (.6 volts) when the outage was occurring.
There is a "black box" connected between the van's taillights and the extension that runs to the outlet connector near the hitch receiver.
I decided that I'd simply replace the wiring harness, which included the "black box" with the exact recommended one, which matched the wiring harness that we discarded. The original trailer wiring harness came with the installation of the hitch approximately two years ago.
After installation of the new wiring harness, the same issues kept occurring sporadically. The guys who put the wiring harness in said that they would replace it...but they couldn't find out what the issue really was.
As things happened, and after the hitch installer worked on the wiring harness with his 12-volt tester, the darn system worked... it worked well, for about three weeks.
However, today it has reverted back to sporadically functioning and then not functioning.
Some additional weird observations....
A. When the Running Lights are NOT working, I can, sometimes, rotate the Light Control on my van, and watch the Running Lights flash on and then off.
B. Other times, rotating the Light Control on my van, causes the Trailer Running lights to start working again and stay on.
C. Today, I noticed a new phenomenon...IF I STEP ON THE BRAKE PEDAL, and at the same time Rotate the Light Control in my van, the Trailer Running Lights come on and stay on???
Now, earlier, I said that this might have been going on for two years. The reason that I cannot verify that is that the original Trailer Harness was used on this same van, but on my other boat. That boat is now in TN. It did not have Side Running Lights, so I had no way of noticing if the Running Lights on that trailer were on when they should have been on, or not. I didn't drive that rig often in the dark, so Running Lights were not required. They may have been working, or they might not have been working.
Wheew.. Long story for such a "simple" problem. I did send a message to Curt Company a week or two ago...(The manufacturer) but never received a response.
This isn't my first rodeo with trailer lights, but it sure has me, and two mechanics stumped.
I believe that it has a lot to do with the "black box" which, as I understand it, is there to "fool" the van's lighting system from shutting off when additional trailer lights are added.
Curt's wiring harnesses even provide for an additional heavy wire to be connected directly to the van's battery so that the new lights don't overload the present van's lighting system
Has anyone else experienced anything like this?
regards, richg99