Cruise control intermittent (2002 Ranger 4.0)

[2002ranger4x4]

I've only owned the truck for just over a month. 78k. The previous owner said the cruise control had a mind of its own. When I turn the cruise "on" and press "set," the cruise control indicator flashes once and does nothing. About a week ago, it worked for a day, then went back to its previous condition.

It passes the self-diagnostic. On the dynamic part of the self-diagnostic, the cruise control servo twitches, but never goes through the full sweep. I've checked the fuses, both brake sensors, and even installed my servo assembly in a friend's ranger — and it worked flawlessly. I rotated all the pins in the servo assembly plug slightly and used di-electric grease to alleviate any connection issues. Still nothing. It has had the cruise control hi-pressure brake cut-off recall.

Any ideas guys?
Thanks in advance.

 

[budro]

Did you check the codes for possibly a speed sensor? Our taurus we had did something similar to that once. Cruising down the interstate at 75 mph cruise kicked off and speedo went to 120 and then back down to 0 and stayed at 0 mph. We just cruised to the next off ramp shut off the car and restarted it and didnt do it again for about a week.

 

[2002ranger4x4]

Nope, haven't run the codes — the check engine light isn't on. I was under the impression that if it throws a code then the check engine light turns on? Never had an issue with my speedometer, but I'm getting to the point where I may have to start replacing sensors left and right even if they appear to work fine.

Thanks for the thoughts!

 

[strvger]

if it uses vacuum lines (mine does), i'd check all those for leaks. next would be all the electrical connections for loose grounds, frayed wires, and corrosion. just my $.02.

 

[Earl43P]

Disconnect and jumper that pressure switch connection to the MC (recall).

I know of two cases where that pressure switch was bad, causing your symptom.

 

[2002ranger4x4]

if it uses vacuum lines (mine does), i'd check all those for leaks. next would be all the electrical connections for loose grounds, frayed wires, and corrosion. just my $.02.

It's all electric in my 2002. I'll give the harness a once over.


Earl- I tested the MC switch but haven't tried bypassing it yet- Good idea, I'll try that this evening.

Thanks again gentlemen.

 

[rva68coupe]

It's all electric in my 2002. I'll give the harness a once over.


Earl- I tested the MC switch but haven't tried bypassing it yet- Good idea, I'll try that this evening.

Thanks again gentlemen.

Hello. Did you ever find the solution to your problem? I just bought a 2002 Ranger 4.0 L xlt Off Road with 79k miles and it has the same exact problem you describe.. with the cruise control light doing a quick blink but not working when I try to engage it.

Love to hear if you figured yours out.

 

[RedRangerSTX]

Bump on this thread.

I coincidentally also have a 2002 Ranger (FX4) in which I am experiencing the same cruise control issue. If I press the set button the light in the cluster blinks on but then goes right back off... It was working intermittently for a while, but now seems to have finally stopped working altogether.

Anyone find a common failure on this issue?


UPDATE: I figured out the problem with a little help from a few other threads. It ended up being the pressure switch on the brake master cylinder. Very easy to diagnose. Unplugged the switch and jumpered the two connector wires, and the cruise control worked fine. Grabbed a replacement switch at a local salvage yard for $5, about two minutes to install, and the cruise works again!