"Thanks VOBD for your interest
Begining to realize now that a sine or Hz is carried on the voltage to/or from the sensors and to the power stage closing transister to force primary to ground to cause spark. Borrowed a meter having Hz reading capablity. Ign.on cranking engine with wrench, probes into crank sensor, see 1.8vdc, switch to Hz and get nothing switch back to millivolts and see surges. seem larger if I crank faster. Is the Hz freq. generated by the sensors? "

Yes, but see below re signal load.
The sensors send speed / position info to the ECU the ECU uses this to output to the coil / injectors etc at the correct timings.

"Maybe need higher cranking speed? "

Yes turn engine on starter.

"Same deal with cam sensor- noHz But surging on mvdc scale. Probes on power stage signal line y/w and blk show signal voltage of .131vdc , no Hz , no mvdc surging while cranking. Either I got the settings wrong or the module is not producing a Hz. Will try again. Removed and replaced several times both modules to ensure good contact"

You don't say if you are trying to measure the volts/hz with the sensor(s) connected to the ECU or not.

The sensors are of a different type and require different treatment.

Crankshaft sensor is a simple two wire AC generator.

Camshaft sensor is three wire and requires the battery supply to work.
Note that some meters will not measure down to 7 Hz but you should see the fluctuations on a meter with a barograph display.

With both types the load of the ECU input is going to make a difference.

The best way is to make up some wire jumpers between the sensor and it's loom connector so you can break into the circuit and measure the values on the signal wire to ground. You should see values near the value I gave. These were for idle so you need to get close to this cranking speed.
If you can get hold of a 'scope all this is much easier to see.

Also the coil resistance of the crankshaft sensor should be between 260 and 500 ohms depending on temperature.
The Camshaft sensor is more complex and I have no values for it.


"tried the site @volvoclub-- didn't go through. beginning to think I may have fouled the OBD memory with all this plinking around and obscured the original pretinant information. Still curious."

You will need to copy & paste the link I gave into your browzer address line as one complete line and hit enter - just tried it - worked for me. Look through the complete thread including the diagram, the info is there.

OBD memory will have stored your attempts so far so you need to read/reset the codes and try starting the car again to have any meaningful info from it.