Hope some of you folks that have been around for awhile and have traded up over the time you've been over the road can pass on some knowledge about the cruise control system on the early model Volvo's. When I am parked and the service brake is applied...I can turn the cruise switch on and can bump the motor up to a high idol. When going down the road I can't get the cruise engaged, My buddy who I hang with and works on the big stuff put his Snap-on puter onto the truck and it said that the cruise was off. He went through the whole system with a test light checking all the pressure switches and the only thing He found was a pressure switch behind the brake valve panel that kept releasing air.....the bottom plug on the sensor was missing. I ordered a new one and put it in but still can't get the cruise to engage. My question is this,,,,,if you get a check engine lite on for a battery in the ecm but don't correct the fault does the bad switch also throw a fault and if you don't clear the fault after you replace the switch...will the ecm override the replaced switch by not engaging??? Do I need to clear the faults to get the cruise to engage? Sure would appreciate knowledge out there from you guys.
OBTW.....I just happened to mentioned the Kansas rally to the DW and she said if we can get some of these issues ironed out on the truck she would feel better bout making the run. as it is now...we're making a run for Charleston on Saturday for the eclipse. good thing is..its only 5 hours from the house and I believe I can dead stick it in to there from here. Will put a post in after we get there. Thanks for your help.