Need to know model. Other than that, a typical Kenworth fuse panel will have a fuse for relay power, and the relays will be multiplexed (although I can't say if this would hold true for a 93 model). If it's only the reverse lamps, and no other systems are affected, your problem is more likely the reverse switch or faulty wiring than a fuse or relay.
The fuse panel is located under the sterriing wheel up against the fire wall.
In the relay/fuse box in front of the battery,small 10amp fuse and 30 amp relay at engine end off relay/fuse block
Where to find the horn relay fuse for a 93 Lincoln Mark VIII
is under the hood were the fuse box is.
The engine compartment fuse and relay box in a 1993 Ford Tempo is on the fender wall. It is located on the same side as the battery.
The blower motor relay in a 1993 Park Ave is located in the fuse box underneath the hood. The fuse box will be located near the firewall.
1. Most Seville have fuse/relay boxes under the hood and the rear seat or trunk.
It's located behind the ash tray in the fuse box.
Could be the fuel pump, fuel pump relay or fuse
Thre is no fuse but a relay on the fuse panel, under the driver side dash. The round metal can is what you want to replace.
I have a 93 Geo Prizm and want start is there a relay if so where is it I have a 93 and it is located under the hood near the battery, inside a fuse box. I believe it is marked as a EFI.
http://www.2carpros.com/forum/automotive_pictures/170934_93_astro_fuel_pump_relay_1.jpg