To access the horn you need to remove the front (plastic) grill, which requires removing about 16 screws including the screws that hold in the curved white/yellow lights next to the headlights. Looking at the truck from the front, the horn is mounted on your left, sort of inside the front bumper. Mine looks like a 3-4 inch diameter circular plate with a single wire coming into it.
To find the horn relay, open the hood, and on your right, about halfway down the engine compartment, you will see a small rectangular object in a rubber shroud, mounted to the wall of the engine compartment near the top, attached with a single screw, and connected with several green/white and red/black wires to the wire bundle coming in from the passenger compartment. That's the relay.
Mazdatruckin.com has diagrams of the Mazda Pickup Truck frames on their tech website. See the attached link.
Under the drivers seat
The SE-5 package has a limited slip differential but it doesn't fully lock.
3,6 litters
99 mazda b3000 where is the speed sensor located
The B2600i does not have an EGR valve, because the truck is fuel injected the ECU monitors driving conditions and retards ignition timing to lower NOx emissions. Kyrasis6 Mazdatruckin.com
left frame rail between tank and engine
the hold light on on my mazda truck b 2600 stays on or flashing and it shut the engine off
I Called the Mazda dealer today and talked with the Mazda Tech and asked him the location of the EGR valve on the 1992 Mazda b2600i. According to the tech only the California models have an EGR valve, I would think that any state with similar laws about vehicle emmisions would require the egr valve also. My truck is from Montana and it doesn't have an egr valve which explaines why I havent been able to find it.
should be in the tank
2500 pounds
The fuel pump relay is located in the cab near the floor behind the driver side kick panel. The attached links below contain additional information about your truck.