I figured my clapped out 1979 528i needed a new turn signal relay. I swapped in a couple I had laying around, but they were all bad. "Okay," I thought, "I'll just buy a new one". Those motherfuckers cost well over $100! The cheapest I could find was $110. Wow, time to get creative.
Eventually, I found that Porsche 914s and a ton of old 911s use a similar turn signal relay. 2/4 x 21w and 4 pins labeled 31, C, 49 and 49a. They are nearly identical with the exception of the configuration of the pins.
I picked one up from Chris at Bartosh Import Auto Parts for $20! That's much better than $110.
To install, we will transfer the wires one by one from the BMW relay connector to the Porsche relay. You can get fancy and buy a relay socket, but I did not because I am cheap and lazy.
Porsche relay:
BMW relay:
Remove a pin from the BMW turn signal connector by depressing the tab on the spade terminal with a commonly available flat blade pocket screwdriver. Once the tab has been fully depressed, remove the terminal by pulling gently on the wire (may take some force, use your best judgement). Then attach the spade terminal to the matching pin on the Porsche relay. Do this four times and you're done. If you ever wish to return to the BMW relay, you can reuse the spade terminals and the plastic connector body. Secure the new relay with a zip tie or whatever.
The part number the Porsche relay is 914 618 303 11. You're welcome!
