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Mambeau / Admin
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(1) Does the ignition have to be 'on' for the SRS light to shine dimly?

(2) I'm not understanding the 'switch to the driving lights' bit at all, so I don't know what's been moved to 'the other side'.

(3) Here (attached) is the '97 SRS wiring diagram. The warning light in the cluster is wired in-line from the 15A ECU-B fuse to the Airbag Sensor Assembly (the SRS 'brain'). The lamp's circuit also happens to be cross-connected to the DLC1 within the 3A connection.

Two things come to mind. The first is that the LED lamp's resistance is so low that it glows just because it's in-line on the power feed (fuse) side of the sensor assembly.

However ... I can't figure out how the lamp is activated in the first place. If it's in-line in the power feed line one would think it should be constant-on unless something inside the sensor assembly activates that circuit's connection to ground. Toyota historically prefers negative switching - i.e., closing / switching the circuit on the grounding side of the component / unit rather than on the power input side.

The second thing that occurred to me is that in (re-)running wires you somehow disconnected one of the two ground lines from the sensor assembly and you're getting some sort of mild current feedback on the circuit in which the lamp is wired. The sensor assembly has 2 ground lines - one each running to the right and left kick panel ground points. Without knowing what's going on inside the sensor assembly I have no idea how realistic this theory may be.

The first thing I'd do is swap the SRS warning lamp back to an incandescent bulb to see if that fixes the odd behavior. If it doesn't stop the warning lamp glowing that probably means the fault isn't just a matter of a sensitive LED bulb.

Hope this helps ...


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