I have a loose orange wire (thicker wire) by the pedals and the fuse box? Where does this go? My signals come on but they don't flash. And sometimes the speedometer goes dim starting at 0km/h and fading up to the higher speeds?

Any help would be appreciated.

THANKS

1991 mustang (non 5.0)

 

please can someone help I think maybe the reason the speedo was going dim was cause low batt power. i sprayed some neutralizer on the posts, but this hasn't fixed the flashers. I also have tried changing the flasher and that didn't work.