CUTLASS 1987 Cruise control inoperative

JAMES L EUBANK

Not-quite-so-new-guy
Feb 18, 2018
30
18
8
CLARKSBURG, WV
#1
Can anyone give me the basic steps to diagnose my inoperative cruise control. This is on a 442 with console shifter. It appears that everything is stock. Wiper and turn signal controls work, but nothing on the cruise control switch. The only other item that does not work is the windshield washer. The windshield washer problem could be related or not. I haven't tried to figure it out yet. Any help is appreciated.
 

UNGN

Comic Book Super Hero
Sep 6, 2016
2,599
1,037
113
Southlake, TX
#2
There are multiple thing that can make the Cruise inop, the stalk switches, the brake switches, the cruise module or the Servo.

You basically have to to test each system individually until you find the issue. With Cruise control, because the actions caused by the switches are too far away, its best to have a helper, with good ears.

First, verify the fuse is good. On some G-bodies there is a fuse spot that says "Cruise". I like to put the rear axle on jackstands so you can test it, when it gets to that point.

Turn the key to run and turn on/off the cruise button. Your assistant should hear clicking under the hood, when its turned on. If not, diagnose if power is getting to/from the stalk switches. There is usually a 4 wire connector under the steering column you can check for voltage changes when the CC is turned on/off.

If the stalk has power, Start the car turn the cruise on and set it and verify you have vacuum at the servo. If not, find out why not. If you have vacuum at the servo, look for tears in the rubber servo bellows. Pinch any tears closed with your finger and see if the cruise starts working.

The last thing to check is the CC brake switch, See if the continuity changes when the pedal is depressed.

The Cruise has a solid state module that could go bad, but what usually goes bad is something mechanical, made of plastic or rubber that goes bad or breaks.
 
May 17, 2018
1
0
1
#3
I'm not sure if anyone can help me but here goes ..... I'm a newby to this but im interested in installing a digital intelligenix dash in my 86 cutlass supreme, but im being a little lazy with trying to figure out the correct wiring for things like: fuel gauge, oil pressure gauge, tach, 12 volt, speedo, high beam, dimmer, basically the complete wiring diagram for both connectors which connects the instrument panel. if someone has that info that would be amazing thanks in advance. please help.
 

UNGN

Comic Book Super Hero
Sep 6, 2016
2,599
1,037
113
Southlake, TX
#4
I'm not sure if anyone can help me but here goes ..... I'm a newby to this but im interested in installing a digital intelligenix dash in my 86 cutlass supreme, but im being a little lazy with trying to figure out the correct wiring for things like: fuel gauge, oil pressure gauge, tach, 12 volt, speedo, high beam, dimmer, basically the complete wiring diagram for both connectors which connects the instrument panel. if someone has that info that would be amazing thanks in advance. please help.
Its best to start a new thread with the title of that new thread "Digital Intelligenix dash install questions".

What you are doing is called a "thread hijack" and is generally frowned upon by everyone currently using the internet.

Nobody is going to help you in a thread that has zero to do with the question you are asking. This isn't an "86/'87 Cutlass problems and modifications" thread, this is a "Cruise control doesn't work" thread.
 
Oct 14, 2008
9,270
2,380
113
Gainesville, Fl
#5
I'm not sure if anyone can help me but here goes ..... I'm a newby to this but im interested in installing a digital intelligenix dash in my 86 cutlass supreme, but im being a little lazy with trying to figure out the correct wiring for things like: fuel gauge, oil pressure gauge, tach, 12 volt, speedo, high beam, dimmer, basically the complete wiring diagram for both connectors which connects the instrument panel. if someone has that info that would be amazing thanks in advance. please help.
It's customary to start with an introduction . Once that's out of the way you can proceed by starting a new thread using your question.
 

Ribbedroof

Royal Smart Person
Jan 4, 2009
2,032
645
113
Wellston, OK
#6
Agree with the above 2 posts, and I'll throw this out....buy the factory service manual....on either paper or CD. SO MANY questions on this forum are easily answered by the OE shop manual, and the originals can usually be found pretty cheaply on ebay .
 

JAMES L EUBANK

Not-quite-so-new-guy
Feb 18, 2018
30
18
8
CLARKSBURG, WV
#7
There are multiple thing that can make the Cruise inop, the stalk switches, the brake switches, the cruise module or the Servo.

You basically have to to test each system individually until you find the issue. With Cruise control, because the actions caused by the switches are too far away, its best to have a helper, with good ears.

First, verify the fuse is good. On some G-bodies there is a fuse spot that says "Cruise". I like to put the rear axle on jackstands so you can test it, when it gets to that point.

Turn the key to run and turn on/off the cruise button. Your assistant should hear clicking under the hood, when its turned on. If not, diagnose if power is getting to/from the stalk switches. There is usually a 4 wire connector under the steering column you can check for voltage changes when the CC is turned on/off.

If the stalk has power, Start the car turn the cruise on and set it and verify you have vacuum at the servo. If not, find out why not. If you have vacuum at the servo, look for tears in the rubber servo bellows. Pinch any tears closed with your finger and see if the cruise starts working.

The last thing to check is the CC brake switch, See if the continuity changes when the pedal is depressed.

The Cruise has a solid state module that could go bad, but what usually goes bad is something mechanical, made of plastic or rubber that goes bad or breaks.
Thanks for your help. Much appreciated.
 

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