jglawnyc Posted July 19, 2017 Share Posted July 19, 2017 Hi Reatt'os. Having resolved my sweet green 91's ignition problems and fixing the door panel, I now have "Reatta Fever" and want to tackle my cruise control issue. It won't work and hasn't since I bought the car. No instrument panel lights have every illuminated either for a problem or to show engagement. A while back I figured out how to check the electrical continuity of the stalk switch, and results were that it was OK. In examining the cruise unit yesterday I noticed a mysterious little green connector on a red wired hanging freely, suspiciously close to the unit. Can anyone solve the mystery tell me what this is and where it goes, or suggest how to proceed to bring my cruise unit back to life? Three pictures hopefully accompany this message. Thanks everyone! Link to comment Share on other sites More sharing options...
Ronnie Posted July 19, 2017 Share Posted July 19, 2017 I hate to disappoint but that connector has nothing to do with the cruise control. It's used for fuel pump testing. You should check fuses first to make sure it is getting power. I don't know about your '91 but the cruise controls has a button to turn it ON an off. Make sure it is turned to ON if you car has that button. The cruise control not getting enough vacuum is a major cause of the cruise not working but in that case the light indicating the cruise is activate will illuminate. Link to comment Share on other sites More sharing options...
retired mechanic74 Posted July 19, 2017 Share Posted July 19, 2017 Go into your onboard diagnostics ( Hit climate button and hold down off and warm buttons) if there are codes in ECM BCM clear them out and retry cruise. As far as indicators on the IPC that portion of the IPC could be burned out. Does the IPC show the time and the mileage?? If so then you have another problem If not Your IPC has a problem. Also if that didn't correct the problem check the brake light switch If it leaks vac. or does not return all the way that to could cause the problem. The servo could also be bad put a hand held vac pump on the vac port of the servo and hand pump if servo retracts that part of the servo is good only thing I can think of left would be a interruption in the electoral circuit. Link to comment Share on other sites More sharing options...
jglawnyc Posted July 25, 2017 Topic Author Share Posted July 25, 2017 Thanks Retired Mechanic: Didn't totally understand your advise, but went into diagnostics and I think cleared what were H codes anyways. IPC seems to be working fine, everything lights when I do the test. I don't have a hand held vacuum pump which I'm assuming is a professional mechanic's tool. I bought a new cruise servo and will install when it arrives. Anyone have any advise on the installation? It seems to me that it will be a pretty straight-forward swap-out. Link to comment Share on other sites More sharing options...
DAVES89 Posted July 25, 2017 Share Posted July 25, 2017 Installation is straight forward. Just keep an eye on the clip used to hold the cable on as it will fly. I believe it is held in it's bracket by 3 each 7 mm screws. There are two hoses. When I am in the yard I just remove them and suck on the large hose as my field test. If it holds the vacuum then I know that part id good. Then I install it at home and keep the just removed one [from my car] as a working back up. Link to comment Share on other sites More sharing options...
jglawnyc Posted July 27, 2017 Topic Author Share Posted July 27, 2017 Hey all: Swapped out the cruise servo in my '91 coupe and after I attached the vacuum hoses, took her for a test drive. (OK, OK... I remembered to attach the vacuum hoses after I started the test drive). It was great to see the cruise switches on the stalk working, and the cruise indicators on the IPC light up for the first time since I have the car. Alas, when I engaged cruise control, the vehicle did not hold the speed. Not sure how it works on the Reatta, but in my other older vehicles I felt the accelerator pedal held down somewhat, not in the Reatta. The car slowly fell in speed, it did not accelerate when I pushed that switch button either. The IPC light did go out when I braked, and the "Resume Cruise" light went on when I pushed that switch, but with no actual engagement. I adjusted the rod to the servo by just ever so gently pulling the slack out of the cable head to be snug when attaching to the servo, but not actually pulling it to cause movement of the cable on the throttle body. As per DAVES89, I sucked on the hoses and believe I felt it hold the vacuum, but will try that again tomorrow. Can anyone out there in Reattaworld give me any suggestions? Link to comment Share on other sites More sharing options...
retired mechanic74 Posted July 27, 2017 Share Posted July 27, 2017 Hey all: Swapped out the cruise servo in my '91 coupe and after I attached the vacuum hoses, took her for a test drive. (OK, OK... I remembered to attach the vacuum hoses after I started the test drive). It was great to see the cruise switches on the stalk working, and the cruise indicators on the IPC light up for the first time since I have the car. Alas, when I engaged cruise control, the vehicle did not hold the speed. Not sure how it works on the Reatta, but in my other older vehicles I felt the accelerator pedal held down somewhat, not in the Reatta. The car slowly fell in speed, it did not accelerate when I pushed that switch button either. The IPC light did go out when I braked, and the "Resume Cruise" light went on when I pushed that switch, but with no actual engagement. I adjusted the rod to the servo by just ever so gently pulling the slack out of the cable head to be snug when attaching to the servo, but not actually pulling it to cause movement of the cable on the throttle body. As per DAVES89, I sucked on the hoses and believe I felt it hold the vacuum, but will try that again tomorrow. Can anyone out there in Reattaworld give me any suggestions? One thing you could try while driving is to put your foot behind the brake pedal holding it all the way up and while holding it try your cruise and see how it behaves. If the cruise holds then you have a bad or mis-adjusted brake switch. A small vac. leak can cause steady loss of speed. Remove the hush panel and the panel that covers the steering column mounting bracket to gain access to the brake light switch and do a good check of the vac. hose. I just thought of something else. Before going through all that work, remove the large vac. hose from the servo (It goes to the brake light switch) and apply lung pressure to the hose if you lose lung pressure then there is a leak, then try what I suggested. Hope this gets it for ya. Link to comment Share on other sites More sharing options...
Frogware Posted July 27, 2017 Share Posted July 27, 2017 Just as a 'Caution' when you hold up on the brake pedal, do not pull too hard or forcefully or the brake switch will go out of alignment. This will cause the resting position of the pedal to engage the brake lights to come on and stay on. I did just that one day as I was exiting the car my foot got lodged underneath the pedal. Well I didn't think anything of it until a day later when I went out to go somewhere my battery was dead, I thought strange??? So I charged it up and did my thing. Later on that evening my neighbor across the way called me and said "Hey you left your lights on" I thought no I didn't even turn them on. So I went out and checked and my brake lights were on. So I had to crawl under the dash and re-position the switch which was like it popped out of a bracket, because when I pushed it back in it "snapped" into position. Link to comment Share on other sites More sharing options...
Ronnie Posted July 27, 2017 Share Posted July 27, 2017 It was great to see the cruise switches on the stalk working, and the cruise indicators on the IPC light up for the first time since I have the car. Alas, when I engaged cruise control, the vehicle did not hold the speed. The BCM thinks the cruise control is working. I suspect a vacuum problem. Use these instructions to check out the vacuum lines. Vacuum Line Inspection My cruise had a similar problem and I found the old vacuum lines would crumble in my hands. Link to comment Share on other sites More sharing options...
retired mechanic74 Posted July 28, 2017 Share Posted July 28, 2017 Just as a 'Caution' when you hold up on the brake pedal, do not pull too hard or forcefully or the brake switch will go out of alignment. This will cause the resting position of the pedal to engage the brake lights to come on and stay on. I did just that one day as I was exiting the car my foot got lodged underneath the pedal. Well I didn't think anything of it until a day later when I went out to go somewhere my battery was dead, I thought strange??? So I charged it up and did my thing. Later on that evening my neighbor across the way called me and said "Hey you left your lights on" I thought no I didn't even turn them on. So I went out and checked and my brake lights were on. So I had to crawl under the dash and re-position the switch which was like it popped out of a bracket, because when I pushed it back in it "snapped" into position. Hey Frogware....Thanks I failed to mention that in my suggestions....My bad. Link to comment Share on other sites More sharing options...
Frogware Posted July 28, 2017 Share Posted July 28, 2017 Hey Frogware....Thanks I failed to mention that in my suggestions....My bad. No Worries...We are all here to help, besides I have made my fair share of mistakes on here :S unfortunately that is the result of my health problems. As long as I can get out of bed everyday and still get things done that is all I can ask for. :cool: Link to comment Share on other sites More sharing options...
retired mechanic74 Posted July 28, 2017 Share Posted July 28, 2017 No Worries...We are all here to help, besides I have made my fair share of mistakes on here :S unfortunately that is the result of my health problems. As long as I can get out of bed everyday and still get things done that is all I can ask for. :cool: I thank God every morning just because I awake and every night for giving me another day. Getting old is not for sissies. Link to comment Share on other sites More sharing options...
Frogware Posted July 28, 2017 Share Posted July 28, 2017 I thank God every morning just because I awake and every night for giving me another day. Getting old is not for sissies. I definitely agree!!! Since this is about cruise control I figure I better put a pun in here... Yeah all these young kids 'Cruise' through life they don't know Nothing :D Link to comment Share on other sites More sharing options...
retired mechanic74 Posted July 28, 2017 Share Posted July 28, 2017 I definitely agree!!! Since this is about cruise control I figure I better put a pun in here... Yeah all these young kids 'Cruise' through life they don't know Nothing :D AMEN to that one brother. Link to comment Share on other sites More sharing options...
jglawnyc Posted July 31, 2017 Topic Author Share Posted July 31, 2017 TEST RESULTS ARE IN: I tested the advice of RetiredMechanic74 and to my amazement, it worked....sorta. I did 4 test runs on a small stretch of highway (the Belt Parkway) near my home and the first 2 times the cruise on my '91 coupe worked great! It responded well to the accelerate button, the resume cruise function, and the decelerate function. This all occurred after I put my foot up against the back of the brake pedal and just a tiny slight bit more than gently pulled it back towards me while I set the cruise button. She then behaved beautifully even after I had released the upward pressure on the brake. On the 3rd and 4th test.....nuthin! I gave the brake a little more reverse pressure than before, then a little less, I held it up, I released it quickly....all with no effect. I'm assuming the vacuum lines are fine since it did work and that I should be focusing on the brake pedal switch adjustment or replacement. Do all concur? If I haven't said it before, thanks so much for all the help Ronnie and all the wonderful community of car lovers we have here! Link to comment Share on other sites More sharing options...
Ronnie Posted July 31, 2017 Share Posted July 31, 2017 ...I'm assuming the vacuum lines are fine since it did work and that I should be focusing on the brake pedal switch adjustment or replacement. Do all concur? If I haven't said it before, thanks so much for all the help Ronnie and all the wonderful community of car lovers we have here! I don't think you should just "assume" the vacuum lines are good. If it were me I would check them closely to rule them out as being defective... BUT, I agree that the switch could be bad. My S10 Blazer would randomly kick out the cruise and the problem ended up being the brake light switch. If I were you I would replace it to see if it fixes the problem. I'm glad you like this website and find it helpful. I appreciate all the members here who have offered to much help to keep our Reatta on the road. ;) Link to comment Share on other sites More sharing options...
jglawnyc Posted July 31, 2017 Topic Author Share Posted July 31, 2017 Hi Ronnie: Is this what you suggested? http://thereattastore.com/standard-motor-products-stoplight-switch/ Link to comment Share on other sites More sharing options...
Ronnie Posted July 31, 2017 Share Posted July 31, 2017 Yes, that switch should fit your 1991 Buick Reatta. You should be able to find it at your local parts store. Link to comment Share on other sites More sharing options...
2seater Posted August 1, 2017 Share Posted August 1, 2017 I have never had an issue with my cruise except it does seem to have some trouble with the higher vehicle speeds of today. The reason I ask may be loosely related. Are you suspecting a leaking vacuum dump switch for the cruise to be the culprit or the brake light switch causing the cruise to drop out? EDIT: I think I worded the above poorly. The cruise vacuum dump switch also has an electrical component, which looks like it is what is referred to as the brake switch, but the FSM is not very clear in the wording. Link to comment Share on other sites More sharing options...
Ronnie Posted August 1, 2017 Share Posted August 1, 2017 I have never had an issue with my cruise except it does seem to have some trouble with the higher vehicle speeds of today. The reason I ask may be loosely related. Are you suspecting a leaking vacuum dump switch for the cruise to be the culprit or the brake light switch causing the cruise to drop out? EDIT: I think I worded the above poorly. The cruise vacuum dump switch also has an electrical component, which looks like it is what is referred to as the brake switch, but the FSM is not very clear in the wording. When I look at a photo of the vacuum dump valve I can see an electrical connector on it but when I look at the schematic for the cruise I don't see where it is in the circuit. Only the brake switch is shown as part of the circuit. Also when you look at the diagram for it's physical location (photo below) , the brake switch has two connections (red arrows) but I see no electrical connection to the dump valve. I'm not saying there isn't a electrical connection to the valve I just can't find it. What do you guys think? Dump valve https://i.ebayimg.com/00/s/MTE5Nlg4MTE=/z/oBgAAOSwjRpZVQp5/$_58.JPG[/img] Link to comment Share on other sites More sharing options...
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