GotLean

Last week a friend helped me jump the car after I managed to leave the lights on most of the night. He accidently switched the polarities with the jumper cables and now the radio wont turn on at all. I checked the 3 fuses associated with the radio under the hood, next to the driver's dash and under the rear seat and even switched them with other spares just in case. This is on a 97 E420. I took the car to the local car audio monkey and he told me that there was no other option short of replacing the head unit with an aftermarket and having to pay considerable "rewiring" expenses. When I originally went in, he didnt know that it was a mercedes and said that there was probably a fuse on the back of the head unit that needed replacing. After he found out, he told me that there was no fuse and that this was the only option. Personally, I cant tell whether he is trying to hustle me or not because he said that he could replace my head unit within the day, but when I asked him for the tool to remove it and check the fuses he said that they didnt have such a tool. Any help is greatly appreciated!

sura

Yes, there is a fuse on the rear of the unit. This would be the next logical step.

I'm surprised this shop didn't have the correct tool. These removal keys are not used only on Mercedes afterall; they're also uses on Audi, VW, Porsche, maybe others. Maybe I'm being too critical, I don't know.

Anyway, there should be shops around who can help you. You can also find the tools on ebay, most around $8-$10.

The fuse is a 10A...good luck.