The backup light switch is located on the left side of the transmission. Disconnect the switch connectors, then unscrew the switch.
The 1990 Mazda 323 horn relay switch can be found on the front drivers side quarter panel. The relay switch will be on the inside of the quarter panel.
There is no egr valve on a 1990 Mazda MPV 6 cylinder
in the tank
blown wire/fuse
On a 1990 Mazda MX-6 with a manual transmission, the neutral safety switch is typically located on the transmission itself, near the shifter linkage. It may be mounted on the top or side of the transmission housing. This switch ensures that the engine can only be started when the transmission is in neutral or park, preventing accidental starts in gear. Always refer to the vehicle's service manual for the exact location and procedure for inspection or replacement.
in the gas tank ?
you should be able to find a shop manual at the local library with the right information on this -- make copies of the pages, as they are usually for REFERENCE only...:)
Yes.
Underneath the car bolted to the bellhousing on the gearbox
The switch is located on the driverside just past the fuses towards the break pedal.
The brake light switch is located on a bracket behind the brake pedal support.