"Reference Sensor w/ignition in position III:
1 - SB Good ground
2 - SR ~12v <----------------- What color is SR?
3 - BL ~3v

Are these correct? Does it mean anything?

Can't say for sure. My EZ 116 K diagram (for '93 940 shows RPM sensor as):
1 - R "signal" to ICU pin 10
2 - BL "signal" to ICU pin23
3 - SB Ground in ICU via pin 11
So I'm not much help there. And my Fault Tracing Manual, while applicable to 700 1988 on, is the Regina/Rex version.

Have you checked for OBD codes?

--
Bruce Young,
940-NA (current)
'80 GLE V8 (Now gone)
'83 Turbo 245
'73 142 (98K)
'71 144 (track modified--and still here)
New 144 from '67 to '78
Used '62 122 from '63 to '67