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Old 12-04-2021, 06:11 PM   #1
Join Date: May 2018
Posts: 32
2018 Isata 3, Driver-side Brake Light and Rear Driver-side Turn Signal not working (Pr

Hope this helps others. My driver side brake light and drivers rear turn signal stopped working but all other lights worked. After trying to trouble shoot (Fuses and Connections) I ended up dropping her off at the Mercedes dealership. After a 3 week wait for an appointment and another three weeks at the dealer they pulled it in for about an hour and told me it wasnít a Mercedes problem and it had to be something on the coach side. Seems like all the RV service centers are booked through May 2022. Using a test light and probing my wires I determined that I had power for my drivers turn signal going into the Hopkins Pulse Width Modulation Converter, but none coming out. There are six wires going into Hopkins Converter and only 4 coming out and it controls your rear lights, brake lights, and turn signals in the rear. Somewhere inside the converter, your brake light is assigned to the left and right turn signal wires. Going in you have ground (white wire), left turn signal (yellow wire), right turn signal (green wire), tail lights (brown wire), brake lights (red wire), battery (red or black wire). Coming out you have tail lights (brown wire), right turn (green wire), left turn (yellow wire), ground (white wire). The gray six pin and 4 pin connector that are used to wire your Hopkins converter in are called Deutsch connectors. The specific ones on my rig were Amphenol AT04 -4p and AT04-6p (4 and 6 pin). I purchased them online after googling them. I attempted to purchase the Hopkins converter from Dynamax parts department but was told they could only sell it to an authorized installer because it was a liability/safety issue. Luckily Amazon didnít feel the same way and I found one there under this number (21146375). You will have to modify the one you get by adding the in line fuse and cutting off the 4 pin flat trailer connector. You will need to crimp on barrel connectors that come with your deutsch connectors to the end of wires. I did this today and know I have working tail lights and break lights. The Hopkins converter and connections are all located under the rear of your coach near the back bumper. It should be zipped tied up near your fresh water tank. Iíll add a few pictures. Sure hope this helps someone. I spent a lot of time on this forum piecing together what I needed to do. First Pic is old then next two are the new controller.
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light, turn signal

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