Does anyone have some ideas on where to start looking for a problem ??

 

Checking the fuse.

Making sure the cable is attached to the bellcrank for the throttle.

If vacuum operated, making sure the actuator is getting vacuum.

Checking the elec plug at the actuator for power.

IF that's good, then getting a meter out and putting it on ohms. Then pull the plug off the Cruise Control Unit. Look at the wiring diagram and you'll see that when you select a function, all your doing is putting a ground on a wire going to the Cruise Control Unit.

So say you select SET. SET sends a gnd signal to the Green/Orange wire at the Cruise Control Unit. So if you had your meter lead on the pin for the Green/Orange wire in the plug, you'll see a reading of less than one ohm on your meter as long as you hold the button to SET. Assuming you put the neg lead of the meter to a good chassis gnd also,.

Same with going to Coast. You put a gnd on the Blue/Red wire. And on and on for the other functions, Main, Resume, Set, Coast.

The Black/Yellow wire should have batt voltage on it with the key to ON.

OR, if you got this far, you might ask yourself a question. Did the cruise work in the near past???? If it did, there is another thing that can cause it to not stay engaged. A bad clutch switch or brake switch MIGHT be putting a gnd on the Cruise Unit all the time. Anytime a gnd is put on the Cruise Unit from these two sources, cruise SHALL NOT be engaged. So check the YELLOW wire on the cruise unit for a gnd signal. It should not be there unless you press the clutch or brake.

I'd post jpgs but I'm pissed at the low life monitors on the SAFC forum who obliterated the jpgs I'd posted there to help SAFC users wire up their SAFC's . You can be sure there's a half assed thread in the archeives on how to install fuzzy dice on the mirror or **** up a engine by removing the *RATS NEST* (DUMB *** DOESN'T EVEN KNOW WHAT HE'S DOING). Pissed

 

who needs cruise control?

 

Cruisers

 

You didn't say if the problem was with an S4 or S5. On an S4, the "Shift Up" light and cruise control are a prone to failure by the breaking of a small plastic tab located on the clutch pedal. If the "Shift Up" light does not come on, there is a good chance the plastic tab is broken and the relay plunger (engaged at the top of the clutch pedal) is just going into the hole formerly occupied by the plastic tab. If this is the case, the cruise control won't work.

I am not sure if the S5 uses the same system for the cruise control.