I have a new to me 1989 190e 2.6 33k miles. There is a wire (aftermarket) that is coming out of the fuse box and I am trying to figure out what this is for and why would it be there.
1. Red wire starts at fuse 19 and goes across the car at the firewall. It terminates in the relay behind the battery. I am not sure what the relay is. My assumption is that the "jumper" wire is energizing the relay because it is not getting its own power through the socket. But I am not sure. There are 2 other parts to this mystery that I will add to the post later but I want to try and figure this out first. This car sat a lot of its life and did have some known rodent damage.
The car had a fully installed car phone and an aftermarket stereo, other than that... stock.
What do you guys think this could be for?