Where is shift modulator on 90 e150 ford van has a e40d tranny?

On a 1990 Ford E-150 van with an E40D transmission, the shift modulator is typically located on the driver's side of the transmission, towards the rear. It is a small cylindrical component connected by a vacuum line. If you're having trouble locating it, consult the vehicle's service manual for a detailed diagram or further guidance.