Good News! Sounds like the problem is inside rather than under the car.

Here are the 4 components and the wiring that connects them...

1) Fuse 11 (200) or 12 (700/900) supplies voltage to items #2, #3, and #4.

2) The Shifter button/switch turns the OD relay off and on

3) The OD relay controls the Upshift ("OD off") Arrow light and the OD solenoid (separate wires). When the Arrow light is ON, the relay and solenoid are OFF

4) The OD solenoid allows OD engagement when ON, (the "default" OD relay/solenoid state at Key On)

Since the Arrow light is goung on and off at random, it's probably the relay. If you don't need or use the switched downshift to 3rd, you can bypass the relay with a jumper wire (making OD totally automatic) as follows:

Put a jumper wire in the OD relay harness connector plug to connect these two terminals together:
• Input terminal #15 (2 wires, a Blue and a Gray)
• Output terminal #87 (White wire)

A good-fitting jumper can be made with flat male crimp-on terminals that are the same size and shape as the relay terminals. The jumper will simulate a relay that is always energized — which is the normal condition anyway, unless the shifter "Downshift" button is pressed.



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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.