[villagetinker]

There are kits available search for Signal Dynamics, they have 3 different versions, also you can search for motorcycle turn signals. As I recall the signal dynamics can be used with MOST existing turn signal switches but work best with momentary type switches.
The villages discount golf carts has an electronic module (~$150) and turn signal switch (~$100) that works with the RHOX wiring harness (cost ???). You can also do an internet search for kits for golf cart accessory vendors.
A word of caution all if these seem to use an electronic module to control the lights and provide the self cancelling feature, these do NOT like wiring errors and always seem to fail before the fuse blows!
I have also seen inexpensive kits (for motor cycles) that provide a beeper signal when the turns signals are active, this is usually 2 diodes and a beeper module and usually under $20.
Hope this helps.