Cruise Control Failure

[The_Epsicle]

So I'm moving to college this weekend and as I'm driving my 1994 Ranger automatic 4.0 the 200 mile trip I hit a bump on the interstate while going 70mph, suddenly my cruise shuts off and does not work the rest of the trip. I had the CEL light up about 160 miles (and about two 10 minute breaks) later and it went off and on until I drive the 10 miles remaining in my trip. I checked the codes and KOER didn't have any, but KOEO had two codes in the memory (sorry, didn't write them down) both for the left side O2 sensor which I've known is getting finicky but I figured I'd include it here, so I cleared the codes. I've had issues with the cruise control not taking a set until it warms up, but I've never had it cut out on my before. Any ideas of what to look for? I'm fairly unknowledgeable about cruise control systems so any help is appreciated.

EDIT: I have had issues with the IAC, also I recently got my A/C working again.

 

[fastpakr]

I'll try to grab the Mitchell manual tomorrow. It's got a complete walkthrough for testing the cruise system systematically. Worked for me a few years ago on my '94 Explorer. I was able to test the components individually and narrow it down to a failed cruise amp.

 

[The_Epsicle]

Thanks, I appreciate that. I figured I'd mention it's been a few days and the cruise is still not engaging, so I'm fairly certain the system is completely shot. Any and all info would be helpful as I'm not entirely certain how a cruise control system works.

 

[The_Epsicle]

I really need help with this one guys, I have no idea where to start.

 

[alwaysFlOoReD]

free bump

 

[RonD]

Couple of cruise control diagrams here: http://www.therangerstation.com/tech_library/EDiagrams/index.htm

Last 2 listings in the engine diagram section.

Cruise control won't engage if brake switch is on
Or if clutch pedal is down(or NSS on auto), so either of those switches can disable cruise control.

Is there is a light on the Cruise control on/off switch or dash that indicates it is on, and can you turn it off?
Clock spring(slip ring) wire under steering wheel passes the commands to the Cruise Amplifier(brains), if one breaks or shorts no cruise.

Also there is the VSS sensor on the transmission next to the speedometer cable, it is used for cruise, cable is for speedometer only

There is a back up brake pedal system as well, it releases vacuum pressure from the from the cruise actuator(part with the throttle cable in the engine bay).
If this hose or valve should crack or leak then no vacuum at actualtor and no cruise

And the cruise amplifier can just quit.

 

[The_Epsicle]

Thanks RonD, I downloaded those diagrams and I'll take a look at them when I find time.

 

[fastpakr]

Sorry for the delay. This week is chaos at my job. I've had the book sitting at my desk at work all week and haven't had a chance to grab the pictures. Trying to get them right now...

 

[fastpakr]

Here you go, I hope this helps.
View attachment Cruise Troubleshooting.pdf