Hello, I'm having an electrical issue with my civic coupe.

I was replacing interior incandescent lights with LED's and I accidentally shorted the top dome light. The fuse went, and after I replaced it the dome light wont turn off in the doors closed position (even with the factory incandescent bulb.). Before this, everything worked fine. Also before the short I replaced the cluster, trunk and license plate lights, and the dome light still turned off by itself.

Reading the factory diagrams lead me to the ICU. the board looks brand new, 0 burn marks or anything. I replaced a transistor that I thought was bad, checked every resistor, cap and diode. the dome light still stays on, but everything else that the ICU controls still works. I also checked the door switches, they're fine. The only component I cannot check is 3 IC's on the board, because there is 0 info about them online. I've seen some diagrams of ICU's off other hondas, but they are significantly different than mine.

I just wanted a second opinion, is it safe to assume that one of the IC's on the board is fried and that I should replace the ICU?

 

Why don't you try another dome light assembly first to see if it is damaged ? It is much easier to diagnose and replace. If a known good dome light assembly doesn't solve it, THEN replace the ICU.

 

The dome light assembly is fine, I even sanded all the contacts and it passed all the continuity tests from the manual.

I got a new ICU anyway, this one was even cleaner than mine and the light STILL wont turn off? how is this possible. the door switches work too. is there anything left to check? i went over every circuit related to this stupid light

 

After doing some more checks i found that the light green/red wire from the dome light has constant ground. this explains why the light is always on and why the ICU doesn't control it anymore. did anyone else ever have this issue? i really don't want to take apart the whole headliner and re wire this...