Electronic Ignition Module Underhood location

In order to stop all the guessing, use a k-type thermocouple adapter for a multimeter and measure temperatures for locations, under varions driving conditions. Electronic devices typically rise a number of degrees above ambient. The maximum junction temperature of automotive electronics is 125 degees Centigrade or 257 F. I have temperature monitoring in my ECU, with data logging. My ECU typically rises about 10C above ambient, and during warm weather temperature runs between 50 and 60C.

Besides temperature, wiring lengths is another consideration. Keeping distributor pickup leads short, is desirable.