i just bought a 90 civic si for 700 buck... its nothin pretty or you know cool (yet).. but it has a strange electrical problem... all my lights i.e headlight taillight reverse light are dim and my tachometer is freeking out... when i turn my blinkers on only about half of the lights (seatbelt door and ebrake) dim when it blinks and others dont. any one have any ideas?????? ive been goin through the entire car trying to make sure all my grounds are good checking all the wires and what not.... anyone have a similar problem or can give advise... ive been goin at it for like a week now.

 

You may have a faulty ICU (Integrated Control Unit). This module plugs into the under dash fuse panel. It is plugged into the panel at the backside when looking at the fuses.There is a plug (10 pin) coming out of the ICU and then the unit itself if clipped onto the backside of the panel. Be cautious when removing both the 10 pin plug and the ICU itself, you do not want to break anything.

The ICU controls a great deal of electrical circuits, many of which you mentioned having issues with. Honda's are very sensitive when it comes to electrical.

 

change the under dash fuse box.

 

bryse68,

Why the whole panel and not just his ICU? Unrelated question-sort of....what is the most likely cause of an inop tach?