W203Lee

Hi everyone

Knocking on your doors with my hat off.
My 2003 W203 C180 recently developed an issue with the rear turn signals & reverse lights. The front turn signals work fine, it's just the rear ones & the reverse lights.
Where do I start checking. Could it be a fuse or relay.
BTW, the problem started after replacing the battery witch was killed by the alternator over charging.
Your help will be appreciated.

Plutoe

Apply some voltage directly to the bulbs------what happens?

W203Lee

How do I do that?
I'm better with mechanicals than electricals.

Thanks for your interest in in trying to help.

slammer111

When you connected the new battery, did you do positive (+) first? My understanding is that this is mandatory for these cars. Connecting negative (-) first fries a SAM module or two, which may explain your situation.

W203Lee

I can remember connecting neg (-) first

slammer111

Oh boy, you may have fried the rear SAM.

Maybe someone else can chime in on how to actually test a SAM unit. I would look into the fuses for the tail lights. Other than that, you may be looking at a replacement.

The good news is that there are plenty of them available on places such as eBay for way less than the dealer. Not sure if there is any version coding, but hopefully one with the same part number would work. Good luck.

W203Lee

Shooo!
Thanks, I will see if I can find someone who can test it & hopefully repair if at all possible.