Submitted by: flasher2001
Replacing both sets of (large) stock turn signal bulbs with the smaller bulbs that are in most aftermarket signals creates a change in the circuit current, which causes an abnormally fast flash rate.
EXTENSIVE research by my uncle Kris & myself (with help from Ohm's Law) showed which resistor would work without creating too much heat.
I placed a 50ohm 10watt resistor in parallel with each bulb to correct the flash rate. (See diagram) You will have to play with different amounts to get the blink rate where you want it.
Radio Shack has the resistors (271-333) for about a buck.
Other pictures show a "package" of resistors ready to be wired in.