1990 Civic LX.

Using a test light from battery positive post to battery positive terminal, I have a bright light whenever the Hazard circuit fuse is installed. With the hazard switch in the ON position, the light is steady. With the hazard switch in the OFF position, the light will flicker at a pace equal to the hazard flash tempo.

Having searched a bit, I find there is an ICU, which does not appear in any wiring diagrams I can find on the web. Does anyone know, or has heard of a battery drain due to a faulty ICU?

 

check if your tail lights and brake lights are working. try removing the bulbs individually, see if the shorts persists.