In answer to your question, the blue relay behind the dash just to the left of the glove box.

However: Since the dash light and solenoid are fed from the same terminal of the relay, and your dash light works, the problem is in the yellow wire from the relay to the solenoid.

If you are sure there is not voltage at the solenoid verified with either a voltmeter or test lamp, there is a connector above the transmission that can get dirty but is usually only a problem if pulled a apart during a trans removal.

Best way to find. Ignition ON, engine OFF, in 4th with dash light on. Removing and replacing terminal from solenoid should cause it to click. Using both hands, wiggle wire between your hands.

If you did not verify voltage with a test lmap or voltmeter, be sure to check the ground wire. The ground wire loves to break internal to the insulation and not allow voltage through the solenoid.

If voltage verified through the solenoid (voltmeter from ground of solenoid to a few body parts to be sure of metal contact through all the c**p under the auto)and it does not click, the solenoid needs to be cleaned.

I have an instruction pack for cleaning, which I will e-mail off list if you request.

Duane