Thread: low range

Went on a club trip on sunday and my son came along with his '97 4.6hse.
When we got to the first track where low range was needed..... wouldnt change . There was no beeping etc , just nothing. We have checked the wires onto the solonoid and the small switch under the change lever. Is there a separate ecu for the change, or can anyone suggest what might be the cause.
Last time out it worked fine.

I'd suspect the drive motor and, yes, there is a separate control unit under the LH front seat.