Electric brakes 2018 Flagstaff super lite 8529RLWS 5th

[Frankie66]

The display on my 2018 Chevy Silverado 2500hd displays the message check trailer wiring. I can clear the message buy pushing the check button on the steering wheel or unplugging the seven pin connector. I have cleaned and inspected the seven pin connector on the Rv and truck. I also inspected the wiring at each wheel all wires are still connected. The 5th wheel is a 2018 8529RLWS Flagstaff super lite. Is there any electrical/resistance checks I can perform and where can I find the specs?

[Mr. Dan]

Do you have an in-bed outlet for your 7-pin plug? Mine was installed after TV purchase by adding a harness/connection under the rear of my truck. That added harness had its plug tied up with cable ties. My “check trailer brakes” message came from an intermittent “open” in that connection because the cable ties were too tight - folded and opened a connection. Check there.

[clr]

Well if you can unplug the 7 pin connector from the truck and clear the error, the problem is not in the truck but the trailer.
I do not have a Flagstaff so my trouble shooting will be rather generic, others with your unit may be of more help.
I would start with using a multimeter on the 7 pin plug of the trailer. I would place one lead to ground on the trailer with the other lead I would first check to see if any of the pins had 12vdc on them. Pin 7 of the plug may have 12vdc from the battery some do and some do not. If you have voltage on pin 7 mark it and do not contact this pin during the next step. Change your multimeter to ohms leave the first lead connected to the trailer ground. With the second lead check for continuity you will see some number since you will be reading thru the light bulb to ground (unless you have LED type bulbs). The number you read should be some what close to each other, reading thru the bulbs. If there is one lead that is much different that is normally your problem and will have to chase that lead down within the trailer.
If it was me I would start looking at the connection point between the 7 pin cable and the trailer wiring. This is normally some type of connection box, look at each connection this may be your problem area.

[Frankie66]

Thanks for the info. I reached into the recess where the connection is on the hitch and got stung by a bee. Bees were building a nest on the ground connection. I sprayed the area last night and will open junction box today

[satdog01]

Was not sure how you determined that issue was in trailer brakes. I would guess that there would be issue in running lights or brake lights, was One of my lights had the lens installed upside down at factory and filled with water. After I dried out fixture and replaced bulb, wiring issue went away. Did rotate lens a 180 degrees as well. You may try a fuse on a piece of wire from the ground pin to each pin on trailer plug and see what is there as well.

[clr]

Not exactly sure of your truck, but most will display different messages for trailer brakes "check trailer brakes". If your truck display is saying "check trailer wiring" then the problem is in the trailer wiring for the running lights, turn signals or back up lights if so equipped.

If the truck is displaying "check trailer wiring" I would start with the lights. If as you state the truck display clears when you unplug the trailer from the truck, the problem is most likely in the trailer.

Plug the trailer back into the truck, and walk back and see if any lights are working or not. I would test the running lights, as well as both turn signal lights. Of course this could be as simple as a burned out bulb or corroded connections.

[Frankie66]

We check the lights every time we get underway, blinker, brakes and emergency flashers and running lights . I also checked the junction box on the Rv hitch and everything looks ok