Reverse Lights On My Trailer Are Pulsing When Plugged Into My 2017 Mercedes-Benz Sprinter 2500 Van

Updated 11/13/2025 | Published 11/10/2025

Question:

2017 Mercedes Sprinter 2500hd Cargo van 144” I bought the van from factory with 7 way connection for a trailer l. I added reverse lights to my trailer and connected to my reverse signal power wire in the junction box and when I shift the van into reverse they just pulse every 3 seconds. I tried a different veichle off mine a 2024 Chevy Colorado z71 with tow package and when shifting into reverse the lights function as is and normal. Will this adapter fix that issue on the sprinter ?

asked by: Hugo

Expert Reply:

Hey, Hugo!

What you're experiencing is pretty common for European vehicles sometimes, but part # 20142 wont fix this issue. I do have a question, did all the trailer lights work find before adding in the reverse lights? My other question would be have you tested the circuit on the van's 7-way to see if its pulsing at all when in reverse.

expert reply by: Gwendolyn Y

Hugo

11/12/2025

Yes, all lights work and function properly except for when switched to reverse. I have not yet tested the 7way yet.

Gwendolyn Y.

11/13/2025

@Hugo I'd say to test the 7-way first just to make sure that's working properly. You may need a load resister like part # P230004A. We do also have an adapter, part # C57003, so you don't have to do any wiring.

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