1992 Airbag Module

bicknell said:

I appreciate the additional information. For the record, my module is alternately working and throwing a code 13, which is the RH front sensor bad. I've tested the sensors and wiring and I'm pretty sure they are fine, so I think my "repaired" module is still flakey.

I'm not sure if the Ford and Mazda operate exactly the same, but here's how I understand the Ford wiring. There is a deceleration sensor in the A-pilar, and three crash sensors across the front of the car. To set off the airbags takes the deceleration sensor closing, and then any one of the three crash sensors. The module checks all three to be sure they are open (really, 1200 ohms resistance) when the key turns on. If the car is started 3 times with a faulty sensor, it activates the resistor and blows the thermal fuse. The large capacitors down the side of the module store enough energy to set off the airbag even if the 12v system is no longer operational for a few minutes. The wiring diagram is basically capacitors -> a-pillar deceleration -> clock spring (airbag) -> module -> 3x crash sensors -> module ground.

Your warning is a good one though, having that fuse disabled would increase the chance of an errant deployment if a sensor was bad.

I'm kinda at a loss as to what to do next though. Even with the capacitors and MOV replaced there are clearly still flakey components. My board from the desert is better, but still not perfect. Both my boards show moisture under the solder mask.

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