EF32RLNP:
Unplug the stock flasher from the socket, then insert the EF32RLNP into the socket.  Ground the black wire to a piece of bare (unpainted) metal, no fuse is needed in the ground wire   In most cases it's easiest to find an existing screw within reach, otherwise use a sheet-metal screw.

Socket terminals are
usually not marked

EF32RL:
Follow the same steps as for the EF32RLNP.  If the turn signals work, you are DONE!.  If not,  the vehicle's socket for the flasher is wired incorrectly (the 2 wires going to the socket are transposed).

There are 3 different ways to correct this:

1. Use the EF32RLNP instead, that model does not care which way the socket is wired
   
2. Rewire the socket so that it meets SAE standards (swap the wires going to the socket)
   
3. Use a reversal harness (one end goes into the socket, the other end goes to the flasher)
   

Plan B: Rewire the socket

If the socket is a stand-alone socket (i.e. not part of a bigger fuse block), then it's usually possible to remove the socket's terminals from the socket body/housing, swap them over and re-insert them.  This can usually be done without cutting wires, but you may need a very small screwdriver to release the terminals from the housing.  If there isn't a real "socket housing" but just 2 wires with push-on terminals, then swapping the wires over is even simpler.  This is usually the case for motorcycles.  However, if the flasher socket is part of a larger fuse/relay block, it is usually impossible to re-wire the socket because it's very difficult to get to the back of the unit to access the terminals, and they may not even be removable.  In this case, you should either go to Plan C or, if all of this sounds like too much hassle, you can simply purchase the EF32RLNP instead.  The EF32RLNP does not care about the socket wiring, it will work regardless of the polarity.)

If you are using the harness (either to correct the polarity or to bring the flasher closer), you may also want to purchase a flasher bracket from Memotronics, part number BR1

EF32RL & EF32RLNP

If you're wondering why the old stock-flasher worked if the wiring is incorrect, the answer is simple: The older-style thermal flashers were essentially electro-mechanical, they didn't contain any "real electronics" so they were not sensitive to which prong the power came in and on which prong it left.  With that being the case, car manufacturers didn't take too much care in the wiring harness design (or wiring-up of the sockets).  The official standard is that the power comes into the flasher on the X-prong of the socket, and leaves on the L-prong (X = Battery, L = Lamps).  Electronic flashers (except the EF32RLNP) require the socket to be wired according to SAE standards.

Plan C: Reversal Harness

A reversal harness is just two wires with male and female terminals at the ends.  The male end is plugged into the flasher socket, the female ends are attached to the flasher prongs.  If you have the tools, you can make your own with 2 pieces of wire, 2 uninsulated male push-on connectors and 2 female INSULATED push-on connectors.  Alternatively you can purchase a ready-made harness from Memotronics, part number EF2C (approximately 2 feet overall length).

Installation