Hi Peter,

At a glance, the only concern that may prevent you installing the later cruise control system from (89-90?) 91-93 is the connection to the back to the dash head. There is a two prong connector, that you may find fitted with a piece of yell and black rubber hos to prevent a short. I think this two prong connection delivers the speed info, as pulses per time unit.

Art B. is among the best on the brickboard to answer this question, though others should chime in that are in the know. At least more in the know than I.

Else, all should install, more of less. Yet you may be better off canvasing the salvage yards and pulling the components schema out of it.

You may also be able to pull components from similarly vintaged 700 and early 900 (maybe before Bosch Motronic replaced LH-Jet on 940?)

I have seen diagrams and manuals for the cruise control system in Volvo 240/740 floating around. Or at least links to them.

A place to start you search for information is:

http://www.volvowiringdiagrams.com/?dir=volvo/240%20Wiring%20Diagrams

From the site:

http://www.volvowiringdiagrams.com/

Questions, comments, corrections, suggestion, recommendations, and so forth.

Hope that helps.

Brickboard Denizen