I have a 97 Avenger 2.5 in the last week and a half has come a long ways from where I bought it. The car came to me in limp mode, I replace the VSS input and output sensors which caused the limp mode to become intermittent. After diving into the problem further I found at some point in time somebody had cut the wires for the output sensor, twisted and taped them back together. I removed the badly corroded wires, soldered them back together, covered them with dielectric grease, shrink wrapped each solder joint, then shrink wrapped both wires together after squirting another good shot of dielectric grease in the wrap. Great the car is running and driving perfect. Then suddenly the lower ball joints start creeking and groaning, the joints are still nice and tight so I drilled a hole in the bottom of the ball joint with a #3 drill bit, tapped it with a 1/4 - 28 bottoming tap, threaded in a 90 degree grease zerk then greased the ball joint until I saw the rubber boot swell slightly. I did both driver and passenger sides just in case the driver side decided to join in. Now the car runs and drives like a dream, steering is nice and tight, handles like its on rails and has plenty of get up and go. Now the ONLY thing not working on the car is the cruise control, I can turn it on and when I hit set/accel the green cruise control light comes on in my instrument cluster however the cruise fails to engage. I did note there is a relay on the black box located on the passenger side of the car which I assume is the cruise relay I will check it tomorrow but any other thoughts would be much appreciated!

 

Check the cruise vac lines they feed from the manifold to the "black box" on the passenger side. With age they crack and will not hold vacumn to allow the computer to hold speed
I've seen the rubber boots crack as well and have seen the black box have a crack in it

 

I looked a little bit last night but didn't see any vacuum lines going to the black box.