How do you repair the cruise control on a 1994 Ford Explorer XLT that works for 2-3 days only after driving on wet roads?

I have a '90 Mustang with cruise control. Mine wasn't working - the EEC IV code said "Speed Controller not working". I found that the plug was unplugged from the gearbox by the speedo cable. My guess, and it's only a guess, is that your plug is plugged in correctly, but not contacting properly - after a while, the water gets into the plug/socket and makes the contact. Get underneath the motor and check the connections are clean and tight. Also, try using a computer tester to drag the codes out of the ECU - it may give a better answer.

Check for vaccum leaks a pinhole can make cruise fail only sometimes,and when you climb a hill you decellerate and never go back to your original set speed good luck