From where to where did you measure 69 ohms? And have you grounded your machine’s feet or not?
You could check if you have this issue:
you could check if you have this issue (without the need to disassemble the end caps shown) with the method described here. I should be noted that with the issue @TheyCallMeJohn had the the other day (he already mentioned it above), the short between inner cable and rail only popped up as a motor error on controller display after John had grounded the machine. Without this, the short does not produce a motor error and remains undiscovered, but remains disturbing the machine’s function at random moments.
I would double-check the possible issues described in the already mentioned posting, especially 7) End Nut Adjustment :