Quote Originally Posted by IC2
I find it discouraging that something so evidently simple as an electronic signal flasher has virtually no internet write up as far as how they really work. Then, the two prong version should be a direct plug in, and in the case of these, a separate ground to complete the circuit. Of course some of the foreign make and commercial vehicles use up to a 13(or more!) pin flasher.

If anyone has found a good write up, let me know - though at this time it's just for my information.
IC2, things I know about flashers.. "older" style did work on thermal action as described earlier. "2nd" generation was electronic in that it didn't rely on a thermal action that would change based on load. i.e. when you plugged in a trailer. The additional lamp(s) would add load and cause a rapid rate of flash.

I don't know what is used to "time" the flash rate of the electronic type, I just know it isn't thermal. I also know that the 2 prong flasher is simply used for "straight through" flasher activation and a 3 prong flasher uses the 3rd prong to activate a common indicator light.

I learned the above info because I just finished adding in the directionals into my car. To add another complication, I used an 1157 bulb up front (turn & running light) and LED's in the rear! It all works fine as long as I used the 3 prong electronic flasher. I used a Lime Works directional switch where the end of the stalk (lever) lights up \ flashes when a turn is indicated. So I had to build jumpers from the fuse box (where the 2 prong flasher plugs in) over to the 3 prong flasher and the open prong goes over to supply the turn signal indicator in the stalk / lever.

Hope it helps some. I'm in CT. this week so I can't give you the part # of the flasher, but, it was a grote... Clear body too if I remember right..