So, this has started happening a few weeks ago, and it is occurring more frequently. First thing in the morning, after I back the car out of the drive way, I drive away in first and the CD player turns off and turns back on as soon as I let go of the clutch. After that, >75% of the time I hit the brake pedal the CD player resets and the gauge cluster dims a little. If it helps, the power for the speedo runs through the CD player.

I thought maybe this could be a sign of a failing alternator, but both the battery and alternator tested fine. Tomorrow morning I'm going to start digging through the car to find the culprit, but does anyone have any ideas?

 

This is a US spec FD, too. Sorry for not including that. It was sort of late last night.

 

Is the ground wire on the battery tight? same with the power wire? my fc kept dying every time i hit the brakes and it turned out to be my ground on the battery haha.

 

Yeah, I checked both terminals on the battery. So far, the problem persists, but the car is staying garaged until all the snow melts, anyways.

 

Check where the ground bolts to the body and make sure its not loose-clean the grounding surfaces off with sandpaper too so it makes a better connection.

I'd check all the other grounds too and clean/tighten them.

Rotary >Pistons

 

I agree, you should check the battery terminals but also make sure all the fuses are making a solid connection as well as the fuse block next to the two ignition coils ,basically make sure all your connectors are clean and tight.
I had a similar problem a few years ago when my headlights went out. It was a dark winding road in the country. Scarry!
Haven't had the problem come back since I did some housekeeping.

 

also have you replaced anything like say the alternator, that has has a ground that is a major player in the car running correctly?