To set the stage I wanted to tackle the easy job of replacing a missing bulb and socket for the in-speedo turn signal indicator on my 66 beetle. However it was not so easy, the 66 was converted to 12v before me. They did a great job, and I should have assumed if they skipped this step, it was an odd one. In the previous post I mentioned that to my surprise the in dash bulb is center negative, so you are switching the negative signal on and off via the relay. I ordered what may be the right part from Wolfsburg West. But a successful test with a random transistor made me think a generic relay from the local parts store would work while I waited. And to be honest, I understand electronics more than mechanical so I was looking for win to boost my ego.
We start with the Dorman 84601. A 4 pin relay that is 12V/30A.
I hooked this up to my bench power supply and supplied power the following way:
- Positive signal from the existing flasher relay to pin 85
- Ground to pins 30 and 86
- Output from 87 to the bulb.
On the bench this all works.
So now it is time to hook it up to the car. Well the in speedometer flasher indicator light turned on, it just did not flash. That said, it did operate at full brightness, so one step in the right direction. What I am learning is that cars are not robots or IoT projects… this stuff is confusing. It is too cold, so this will probably just be swapped for the Wolfsburg West relay to see if it works.