Looking in my factory service manual for a 1989 Chevy Celebrity I found no reference to an accessory relay.
According to my factory service manual the horn relay for a 1989 Chevy Celebrity is located in the "convenience center" which is behind the instrument panel on the left side of the steering wheel. To replace the relay one would simply pull out the old relay and plug in the new relay.
It is behind a cover on the driver side strut tower.
Under hood fuses are generally located next to the relay they are for.
The oxygen sensor on a 1989 Chevy Celebrity is located in the rear exhaust manifold on top about the center.
The thermostat on a 1989 Chevy Celebrity is located under the water outlet fitting. Follow the upper radiator hose, it will end at the water outlet.
Looking in my 1989 Chevy Celebrity manual I find a park relay inside the wiper motor but no reference to an external wiper relay. There is a fuse on the fuse block.
location of the fan relay switch on a 1989 Chevy Corsica
Underneath your hood, behind the passenger side headlight, behind the core support, is a bank of 2-8 relays. One of those relays is the relay needed for your fuel pump. There will also be a fuel pump relay fuse located there.
The fuel pump relay is located on the radiator support bracket on the passenger side of the vehicle. It is the center relay.
The petcock on a 1989 Chevy Celebrity is at the bottom of the radiator on the drivers side.
inside the fuel tank