I’m a one-owner of a 1999 Mazda Miata which has developed a weird cold weather glitch. Whenever the temp drops below about 40 degrees (F) the air-bag warning light in the dash begins to blink: it blinks three times and pauses, then blinks four times and pauses, then it repeats the cycle endlessly UNTIL the outside temp warms up. If the outside temp stays forty or below the blinking never stops! In addition, the passenger airbag OFF light doesn’t light up as long as the blinking continues. (I normally drive solo so I keep the keyed passenger airbag set to OFF). On warm days everything’s fine: no dash light blinking and the passenger airbag OFF light illuminates properly. How can cold temps be causing this problem?
The 4 blinks would make sense on an earlier Miata but I don’t see an entry for a code 4 on a 1999. A 3-blink code, however, indicates a bad power connection.
If I had to guess, there’s a wire break or a plug is not seated properly, and when it gets cold the wire contracts enough to break the circuit.