strobe lights
Thanks, Justme69 and others for the enlightning info on the RAT-heater and TOWS relay issues.
Concerning the strobe lights, I thought the MD-80's strobes would only come on on change to "air mode" of the signal in the N/G strut, as discussed in earlier posts. I have been able to verify that this is indeed the case as a passenger during 4 SAS MD80/90 operated flights earlier this week: N/W lift-off: strobes on; weight on N/W on landing: strobes off.
So, the earlier question on which relay the strobes are is indeed an interesting one, if (as a mechanic on the ground seems to have declared after the accident) he saw the strobes of HFP working when it taxied away from the ramp for the fatal take-off.