Lane A status light partially illuminated

Assuming you’re using LED it sounds like you don’t have a resistor on that bulb or it faulty or not connected properly.   

edit: sorry I have the 915 installation manual page number.  Forgot which group I’m in, but same concept.   Just need to find in the 912 manual.  

Diagram on page 12 of 76-00-00 in 915 installation manual

Here’s diagram

What Mike Said!  912is and 915is use the same circuit.

That 1.5Kohm (1500 Ω) resistor is Not optional.
The ECU assumes you are using an Incandescent lamp.
In the OFF state, the ECU Lamp driver circuit still leaks a few Miliamps through the bulb.
This will not be enough to light an incandescent lamp but it is plenty to light an LED Dimly.
The side load resistor gives this leakage current a path around the LED instead of through it.

The A and B Lamp circuits are both the same.  Just compare the two.

Thx Bill

Thinking along those same lines, I pulled the PC board out last night and inspected (best I could) with a magnifier and meter.  Nothing appears astray.

what I want to do now is look at some voltages.  The circuit is really simple . . . but maybe it will tell me something.  I have a collection of D-sub connectors, I'll see what I can paste together for a break-out harness for troubleshooting.

Thx again Bill

Mike B