Adding Hazard Warning to Turn Signals

There are times when it is very desirable to be able to simultaneously flash the front anr rear turn signals on both the left and right sides of the car in what is though of as a hazard warning.  In my experience it has been very easy to convert the standard TD turn signal system into a hazard warning system.  The wiring diagram below shows, schematically, how to do the conversion.  All that is needed are 4 common diodes and a SP/ST switch. The diodes are used to allow the hazard system to simultaneously direct the turn signal power to both sides of the car without affecting the normal turn signal action.  Each of the internal relays of the turn signal can draw about .75 amps.  Simple, low cost diodes, such as 1N4004 are adequate for the task.  I chose to use an illuminated sp/st rocker switch from Radio Shack for the hazard switch.  I wired its lamp to the n.o. contact so that lights up if the switch is activated. It's probably worth while using a heavy duty flasher.