MX-5 Miata L4-1597cc 1.6L DOHC (1992)
Check resistance between the following relay terminals.
"STA"/"E1" -
Resistance...21 - 43 ohms
"B"/"Fc"
-
Resistance...109 - 226 ohms
"B"/"Fp"
-
Resistance...infinite (no continuity)
If results are not correct as described, replace relay.
TEST 3 - RELAY CIRCUIT (WIRING) CHECK
Relay Circuit
Check voltage at the following terminals with the relay installed, under the conditions listed below.
3A - IGNITION "OFF"
No voltage at any terminal.
3B - IGNITION "ON" ENGINE NOT RUNNING
Terminal "STA"- 0 volts
Terminal "B" - 12 volts
Terminal "Fp" - 0 volts
Terminal "Fc" - 12 volts
3C - IGNITION IN "START" POSITION (CRANKING)
Terminal "STA"- 12 volts
Terminal "B" - 12 volts
Terminal "Fp" - 12 volts
Terminal "Fc" - 0 volts (or nearly zero)
3D - IGNITION "ON" ENGINE RUNNING
Terminal "STA"- 0 volts
Terminal "B" - 12 volts
Terminal "Fp" - 12 volts
Terminal "Fc" - 0 volts (or nearly zero)
NOTE: Relay terminal "E1" is a ground.
If voltage at any terminal is not correct, check the wiring associated with that terminal.
If 12 volts is present at terminal "Fc" during engine cranking or engine running, and the engine dies after starting, check for open in wiring between that
terminal and the air flow meter connector (B/R wire). If wiring is OK, check fuel pump switch in air flow meter.