[Ether]

If you have 2 known good CIMs and a 2-motor gearbox, you could try the following:

1)

If you have a suitable encoder, install it on the gearbox.

Install the two good CIMs into the gearbox (with no load on gearbox). Run CIM1 with full voltage, and measure the voltage output of CIM2 (unshorted leads). Record the CIM1 applied voltage voltage, the CIM2 output voltage, and the encoder RPM. Now repeat with CIM2 powered and measure CIM1. Record those measurements. This is your baseline.

2)

Replace CIM2 with CIM3 (suspected bad). Repeat #1 and post your measurements here. Replace CIM3 with CIM2, and CIM1 with CIM3. Repeat #1 and post those measurements here.