Troubleshooting Factory 7-Way Connection 12V Power on 2018 Mercedes-Benz GLE
Updated 06/09/2024 | Published 07/17/2021
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Question:
I have a 2018 Mercedes GLE350 with AWD 4MATIC with the factory installed hitch with 7-way connector. I tested the connector using the Curt 58270 tester and all I get is 3 weakly flashing LEDs RT, TM, LT. How do I correct this issue so I get the 12V indicator LED to light up so I can be confident that the Echo will work with my vehicle? Thanks for all you do
asked by: Dave E
Helpful Expert Reply:
According to the instructions for the Curt tester, the light marked 12V should be on constantly once you start the vehicle and perform a function test. Since this is not the case, we will assume the tester is functioning correctly
Make sure the 7-way connection on your vehicle is clean so it there is a good connection for the tester. You also want to inspect it and make sure there isn't any damage. In addition to these two things you can also check the fuse. Each function of a factory connector will be fused individually.
Beyond this there is a damaged wire somewhere, but it could be anywhere so that may be hard to find. You can trace the wire and attempt to repair it or you can run a new wire. If you choose to run a new wire we do have 10 gauge wire # 10-1-1 available by the foot.
Since it sounds like you are planning to tow using a brake controller and mentioned the # C51180 Curt Echo, I'm assuming you will be purchasing one once the issue is resolved. I would consider getting the Echo now, or at least before you start replacing wiring. We do not carry this particular Curt tester so I have no information on its reliability. On the off chance it is not functioning correctly, you may save yourself some work if you tried plugging in the Echo first. The Echo has its own LED which would also tell you if there is power at the 7-way.
I have attached a review of the Echo for your reference.
Product Page this Question was Asked From
Curt Echo Wireless Brake Controller - 7-Way Plug-in w/ Bluetooth App - Up to 2 Axles - Proportional
- Trailer Brake Controller
- Proportional Controller
- Electric
- Plug-In
- Smartphone App
- Under-Dash
- Up to 2 Axles
- Smartphone Display
- Multiple Trailers
- CURT
more information >
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Don S.
6/9/2024
FYI I had the same problem recently with my 2021 Mercedes GLE 350. I purchased a 7 pin tester that reacted like this incident. I had already purchased the Curt wireless brake controller and it did not register any power when connected to the vehicle. I took my vehicle to Uhaul and their tester did not work either. I then took my vehicle to the Mercedes dealer and they tested the system and said it was working properly. They also told me that they have tried several after market pin testers for their shop and have not found one that will work on their vehicles. When I returned home I connected my vehicle to a friends horse trailer and the trailer lights functioned property. I then connected the Curt brake controller and with the trailer connected to the controller the power light worked. My recommendation for any Mercedes owner with a factory installed tow package test their system by using a trailer connection and avoid using any after market pin testers.