Well, on a whim I swapped in a back-up OVP I had laying in my parts box and re-ran the tests.
Still showing 75mA at the EHA with the key on, engine off. During start, the EHA draw went up to 78mA stayed there for about 2 seconds then dropped to 6mA, with the draw dropping to 2mA as the engine warmed. I'm sure the current draw would have dropped lower if I had kept watching. Interesting thing was the draw steadily dropped with the OVP change compared to the numbers fluctuating before the swap.
The duty cycle now fluctuates between 49.3% and 51.9%. The swings are gradual enough that one can watch as the numbers count up, then drop and start going up again. During the prior test the numbers were jumping around wildly, with the majority falling at 50.3. When I say wildly, I mean I couldn't keep track of them because they were changing so fast.
BTW, the engine fired off pretty quickly compared to the way it had been. I will know better in the morning how it starts
Am I on to something here?
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.