96 Escort Cruise Problem

The cruise control on my 96 Escort is giving me problems - it won't latch the desired speed. If I press "set/accel" the car accelerates, but as soon
as I take my finger off the button it just slows down.
Could some kind person point me at the likely problem, as I'd like to minimize the amount of money that I give the local shop.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.