trying to add flashers

hello everyone, I have a small problem on my hands. A few months ago, I installed a keyless entry. I wired up a relay to it so I could have my front lights flash when I locked/unlocked the car. Well the front light had "city bulbs" in them that arent used by the factor harness as they are european light bulbs. So, I wanted to make the tail lights flash just like the front lights. So I spliced off the line that fed the front lights and ran it to the trunk. I spliced it to the tail lights like I wanted and hooked it all up. Well they flashed all right. At the same time the blew the factory fuses for the taillights. Someone had told me to install a diode in the line that I laid to the trunk. So I did, (6a 50v from RadioShack) this prevented the factory fuses from blowing but now my inline fuse for the "flasher" relay blows when ever the keyless is used....I tried putting the diode in backwards/forwards no change... I know I am confused as to how to fix this I hope someone can help me. Here is my diagram of the wiring:

sorry. i forgot the car's info...1982 Mercedes 300SD

it happened to me same situation, try  to use diode in  each stock wiring harness in tail lights