I still haven't been able to isolate my problem. Here's what I did/saw today:
- The battery seems to be holding a charge OK (12.75v).
- Checked and verified good continuity all the way from the small yellow wire at the VR (VREG CNTRL) to the Switch & Fuse Module (AV-50001) via:
- Control Module (AV-50000A) WH-00063 (21) & WH-00030 (14)
- Ignition & Start Module (AV-50002) WH-00030 (14) & WH-00030 (13)
- Control Module (AV-50000A) WH-00030 (14) & WH-00031 (23)
- Switch & Fuse Module (AV-50001) WH-00031 (16)
- Checked and verified that the Master Switch correctly made & broke continuity of the VREG signal between pins 13 & 14 of WH-00030.
- Confirmed battery voltage (12.75v) on the Battery input of the Switch & Fuse Module.
- ?? With 12.75v on the battery input of the Switch & Fuse Module and with the D-Shell disconnected, measured 9.7v on the VREG WH-00031 (16) S & F module output.
- Just to verify another S & F module output, I checked the Fuel Pump output (WH-00031 pin 1) and it was at 12.75v.
- Also measured 9.7v on pin 23 of the Control module end of WH-00031.
- ?? I couldn't figure out how to measure intermediate voltages between the Control module VREG input, WH-00031 (23), but the voltage at the small yellow VR wire continued at the 1.75v I previously saw.
- Visually checked the 1A VREG fuse on the S & F module. There was no visual difference between that fuse and the other two fuses on the circuit board but I have no idea if there's any visual indication if these fuses blow.
So, I'm still at a loss. Tomorrow I guess I'll go out and see if I can see some way to check intermediat voltages between the Control module that's at 9.7v to try to see where it drops to the 1.75v I see at the small yellow wire.
I don't understand the drop to 9.75v S & F module VREG output.