1991 Ranger xlt 3.0- Cruise Control problem

[jameshe1950]

Hi, newbie here,
Bought a 1991 Ford Ranger XLT, 3.0 v-6, Truck has less than 59,000 miles. The issue is the Cruise Control doesn't work. Can't find any documentation in the Haynes manual.
Looking for any guidance, tips, strategy to fix.
thank you for any suggestions.
Jim

 

[franklin2]

The electronic cruise control system consists of the following components:

1. Control switches
2. Servo/control unit (throttle actuator)
3. Speed sensor
4. Stoplamp and deactivator switches

The throttle actuator/control unit is mounted in the engine compartment and is connected to the throttle linkage with an actuator cable. The control unit regulates the throttle actuator to keep the requested speed. When the brake pedal is depressed, an electrical signal from the stoplamp and deactivator switches return the system to stand-by mode. This system operates independently of engine vacuum, therefore no vacuum lines are required.

 

[franklin2]

Apparently they used a vacuum system on some trucks also?


The vacuum controlled cruise control system consists of the following components:

1. Control switches
2. Servo (throttle actuator)
3. Speed sensor
4. Clutch switch (manual transmissions)
5. Stoplamp switch
6. Vacuum dump valve
7. Amplifier assembly

The throttle actuator is mounted in the engine compartment and is connected to the throttle linkage with an actuator cable. The speed control amplifier regulates the throttle actuator to keep the requested speed. When the brake pedal is depressed, an electrical signal from the stoplamp switch returns the system to stand-by mode. The vacuum dump valve also mechanically releases the vacuum in the throttle actuator, thus releasing the throttle independently of the amplifier control. This feature is used as a safety backup.

 

[RobbieD]

Apparently they used a vacuum system on some trucks also?

That sucks!

On a '91, an OEM cruise should be the vacuum system.

First question for the OP:
Are the tail light bulbs the original incandescent type, or have they been changed to LED?

 

[James Morse]

Are the buttons in good shape? Every old Ranger I've ever seen, the buttons were tore to heck (sometimes still work though). You can get new ones cheap and they are pretty easy to swap out, so you could eliminate that easily.
That sure is low miles though, assuming that's the original odometer.
I have shop manuals but probably no help because, I think, your '91 is a different gen. Don't know how different it is from mine. If you could get ahold of the shop manuals they usually have a diagnostic routine to find where the problem exists.
Off topic, but just reminded me of fixing cruise on an '86 Saab manual trans where they had a ball chain arrangement whereby the cruise locked onto the right place on the chain... it was weird, but it worked.
New trucks have + and - for 1-mph incremental up/down which to me is nuts because the '97 already had that, you use the already existing buttons to creep the speed up or down, it works slick as can be.
I guess now it's too hard for people to read the manual.
Do your buttons light up? Some years do and some don't.
If the cruise light comes on the dash but cruise itself doesn't work that would tell you something probably; I assume you get no dash light when you set speed. Assuming it's like mine you have to turn it on first then set speed but I'm sure you know that. Good luck I'm sure you can fix it.

 

[jameshe1950]

The electronic cruise control system consists of the following components:

1. • Control switches
   • Servo/control unit (throttle actuator)
   • Speed sensor
   • Stoplamp and deactivator switches

The throttle actuator/control unit is mounted in the engine compartment and is connected to the throttle linkage with an actuator cable. The control unit regulates the throttle actuator to keep the requested speed. When the brake pedal is depressed, an electrical signal from the stoplamp and deactivator switches return the system to stand-by mode. This system operates independently of engine vacuum, therefore no vacuum lines are required.

Franklin2, thanks for this and your next posting.
Been overwhelmed with life so have not done any more troubleshooting. Especially, thanks for the drawings.
I will advise when i get it fixed.
thanks again,
Jim

 

[jameshe1950]

That sucks!

On a '91, an OEM cruise should be the vacuum system.

First question for the OP:
Are the tail light bulbs the original incandescent type, or have they been changed to LED?

Robbie,
I am guessing original, everything else is stock.
I'll check.
Thanks for the hint.
Jim

 

[jameshe1950]

Are the buttons in good shape? Every old Ranger I've ever seen, the buttons were tore to heck (sometimes still work though). You can get new ones cheap and they are pretty easy to swap out, so you could eliminate that easily.
That sure is low miles though, assuming that's the original odometer.
I have shop manuals but probably no help because, I think, your '91 is a different gen. Don't know how different it is from mine. If you could get ahold of the shop manuals they usually have a diagnostic routine to find where the problem exists.
Off topic, but just reminded me of fixing cruise on an '86 Saab manual trans where they had a ball chain arrangement whereby the cruise locked onto the right place on the chain... it was weird, but it worked.
New trucks have + and - for 1-mph incremental up/down which to me is nuts because the '97 already had that, you use the already existing buttons to creep the speed up or down, it works slick as can be.
I guess now it's too hard for people to read the manual.
Do your buttons light up? Some years do and some don't.
If the cruise light comes on the dash but cruise itself doesn't work that would tell you something probably; I assume you get no dash light when you set speed. Assuming it's like mine you have to turn it on first then set speed but I'm sure you know that. Good luck I'm sure you can fix it.

Hi James,
The whole thing is stock and clean. It acts like the mileage is right. The tires were made in 2013 and show no wear at all. Yeah, I know old tires and rot.
The buttons are clean. I get no lights or anything when I push the ON, Off, and others.
Brake lights work.
The ABS light was on, but I took it to a mechanic and asked for a good looking over. A list of little stuff ( leaky hoses,etc.)
This is a "1st generation" Ranger with the 3.0 V-6, automatic. If it has an OBD port, I can't find it.
I will keep working on it, but is low priority right now, life is throwing me a lot of curveballs.
Thank you for replying and your suggestions.
Jim