Hi, I have a 1989 honda civic hatchback. stock wiring.
Things that work:
Headlights
Turn Signals
Hazards
Reverse

Things that do not work:
all running lights(first click of headlight switch on steering column usually turns these on)
cluster lights
dimmer switch

Dimmer Switch:
Taken apart
found a break in one of the solder joints, re-soldered it, still unresponsive
Checking plug connections
check for voltage from red to black and red/black to black. 0 volts on any setting of headlight switch
check ground for continuity to chassis, has continuity
short from red to black, unresponsive

Headlight Switch(on steering column)
1st one(stock from 89 civic hatchback)
Taken apart
followed video guidance on how to check for breaks, cleaning, and reassembly
gets power to headlights only on 2nd click
no power through on 1st click
2nd one(from 91 crx Si) currently in vehicle
Taken apart
same as 1st

Taken to shop known for working on old EF civic/crx/sedans. owner has 2 RHD, seems to know what he's doing.
Made a jump from RED/GREEN to RED/YELLOW on headlight switch(on steering column)
pic shown

RED/GREEN to RED/YELLOW done by shop.

This worked for a week, then started blowing the 10A fuse for the running lights.




UPDATE: got a new ICU(grey box on the back of the fuse panel) like-new board, no signs of roasting at all.
Nothing has changed.

 

UPDATE: got a new ICU(grey box on the back of the fuse panel) like-new board, no signs of roasting at all.
Nothing has changed.