Troubleshooting Factory 7-Way Connection 12V Power on 2018 Mercedes-Benz GLE

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.

expert reply by: Robin H