No Trailer Lights

[D Porter]

Hey guys,
Just got our '06 1640 out of storage and the trailer has no running lights, blinkers or brake lights. As far as I know they were working when I parked the camper.
I used an aftermarket wiring harness since our Rav didnt come with a tow package. The fuse at the Rav battery is good, and the plug has power to all prongs. Seems like the issue is in the trailer?
Any tips?

Thanks in advance.
Dan

[ChooChooMan74]

1 bad ground
2 mice

[bikendan]

something's wrong between the trailer connector and your Rav's harness.

[D Porter]

I did a quick check of the ground and looked for mice damage but I didn't see anything obvious. I used connector grease to connect the trailer to the Rav harness. Im not sure what else to try?

Thanks for the replies.
DP

[jeeplj8]

I will echo above, sounds like mouse damage.

In order to diagnose, you need to isolate each possible cause. What I would do is make a small jumper from a 12 volt battery (I have found that a lawn tractor battery works great for these kind of things and is handy to have in the garage) with a clip to the battery on one end and a terminal plug on the other. plug it in to each terminal on your camper plug and look for effect. If still no light, you know the problem is in the camper wiring.

It could be damage to the plug itself, that happens. Or a ground problem.

[D Porter]

Alright,
I ran a wire from the positive side of the trailer battery and connected it to each prong of the trailer connector. Bingo, we had power to each light when connected. So the issue is indeed with the TV. The inline fuse off the TV battery is good. Got any other tips?
Thanks for the idea jeeplj8.

[RickV]

Could be some corrosion in one connection or the other. Maybe some contact cleaner or diaelectric grease may help.

[ChooChooMan74]

Originally Posted by RickV

Could be some corrosion in one connection or the other. Maybe some contact cleaner or diaelectric grease may help.

What about the ground on the TV?

[jeeplj8]

Originally Posted by D Porter

Alright,
I ran a wire from the positive side of the trailer battery and connected it to each prong of the trailer connector. Bingo, we had power to each light when connected. So the issue is indeed with the TV. The inline fuse off the TV battery is good. Got any other tips?
Thanks for the idea jeeplj8.

Do you have access to a volt meter or test light? They are fairly inexpensive and should be part of every campers tool kit.

My suspicion is something wrong with your plug. You need to check for power in the wires going into the plug from the tow vehicle.

[D Porter]

It's pulling .5 of a volt at the TV connector.

Have this harness: Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector Curt Custom Fit Vehicle Wiring C55307
and this adapter: Adapter 4 Pole to 7 Pole and 4 Pole Hopkins Wiring 37185

Thanks again.

[D Porter]

Oh, I also swapped out the adapter for a new when, no dice. It has to have something to do with the harness I guess.

[Timtation]

The bare plug is the ground(-). Check it versus the hitch, bumper, any metal that is connected to the frame. If you don't have continuity start with emery paper, pull ground connectors and reattach. With 12V systems it is almost always ground problems. If the 1/2 volt is ground to positive connection on the TV plug it is a good indication of poor ground.

[VinceU]

Originally Posted by D Porter

Alright,
I ran a wire from the positive side of the trailer battery and connected it to each prong of the trailer connector. Bingo, we had power to each light when connected. So the issue is indeed with the TV. The inline fuse off the TV battery is good. Got any other tips?
Thanks for the idea jeeplj8.

I'm thinking since each lamp worked with substitute power supply, and each lamp type is powered by different sources of the TV, the only remaining common denominator is the vehicle to trailer ground connection. Either the plug is defective at the connector or where the TV socket is grounded.

[D Porter]

Ok, I just went out and checked the bare plug and it looks like it just came out of the package, zero corrosion.
I also looked at where the TV system is grounded. It's on the interior of the vehicle and looks good too.

[VinceU]

Originally Posted by D Porter

Ok, I just went out and checked the bare plug and it looks like it just came out of the package, zero corrosion.
I also looked at where the TV system is grounded. It's on the interior of the vehicle and looks good too.

I'm thinking you really need to "ring" these circuits out with a ohm meter or voltage checks. Its difficult to "see" wiring connections when they go out of sight. Wire can chafe and ground, open or melt. You just don't know it's good. Otherwise you have one heck of a mystery!

[D Porter]

For what it's worth, this is the process I used to install it. It may give you some better insight as to how this my system works.

Installation of a Trailer Wiring Harness on a 2012 Toyota RAV4 - etrailer.com - YouTube

[D Porter]

It appears that a rusty ball hitch was at the root of the problem. Is that possible? I'll spare you the details but after a pretty exhaustive process of elimination and a bit of luck/ coincidence, that seems to be the common denominator.
The lights literally flickered to life as I was moving the trailer to a different parking spot.

How about that.

[OldCoot]

Originally Posted by D Porter

It appears that a rusty ball hitch was at the root of the problem. Is that possible? I'll spare you the details but after a pretty exhaustive process of elimination and a bit of luck/ coincidence, that seems to be the common denominator.
The lights literally flickered to life as I was moving the trailer to a different parking spot.

How about that.

You have to run a separate ground from the tv plug to a chassis ground. It will not ground consistently thru the ball.

[D Porter]

Yeah, I have the TV system grounded on the interior of the TV as shown in the video.

[D Porter]

Does the fact that the TV and PU need to be connected via the ball hitch indicate another issue?