Cluster Instrument Light + tail lights went out

[CDCD]

Howdy, reaching out regarding a 1991 F250 Custom.
The other night the light for the cluster instrument and the tail lights went out.
1. Is this a fuse or a relay? How can I tell if it's a fuse or relay?
2. Is there a good resource for locating parts?

Thanks

 

[Fellro]

No relays, just fuses for the lights. The cover for the fusebox generally tells you which one does what.