Convert Switched ground cicuit to common ground to power automotive LEDs

Thread Starter


Joined Jun 20, 2010

Looking to design a low power circuit to drive the LEDs in a new shifter I'm trying to retrofit onto my current car. Problem is, the current design uses a common power and switched ground design to complete the circuit and power the PRND and M/S LEDs. The new shifter pictured below (from a 2010 650Ci) uses a common ground, switched power design to power the PRND and M/S LEDs.

See pics of project and schematic of current circuit below:

Buddies car; gave me the idea; he never got it working....

Schematics of current design in my car. Couldn't find schematic showing actual shifter LEDs. I believe they are attached to signal wire located just above transistor.

I'm looking for a simple low power circuit to utilize the current ground switching through selector lever to trigger a gate, relay or other such device to output a signal to drive the PRND and M/S LEDs on the new shifter.... I'm an electrical engineer, 20 yrs removed from electronics design and unfamiliar with new technologies and devices available to me.

Considering it's for a car, power, size and environemental tolerances are critical. Any suggestions? I was considering a traditional micro relay driving the LED through a resistor to drop the voltage.... Would need 5 duplicate circuits to run the 5 LEDs...... likely NOT the best solution...

Thoughts, suggestions?