Last trip after driving for about 2 hours the Cruise Control decided to speed up > disengage cruise control > foot throttle working ok > reengage cruise control and does it again, continue to destination on foot throttle . On the drive back works ok for about 2 hours then it did it again. I contacted Steve Boller at Cruise King and shipped the unit to him for testing. He could not find anything wrong even though he warmed up the unit to a high temperature. We both suspect the problem is a bad ground. I have read the post on Beam Alarm about King Throttle. Steve also sent me the wiring schematic for the unit. Does anyone know the location of the two grounds? Seems like the main ground should terminate somewhere near the engine and the brake light ground may be near the brake lights. Steve said that he does not know where the grounds are on my coach. From the schematic I know which wire it is, but then it goes into a bundle of wires encased in a jacket with lots of wire ties to hold it in place. If no one knows the ground location, I will be undoing all the wire ties and trying to trace it down. Thanks for your help.
Jerry,
The good news is that you do not need to trace a ground-- just add another one to good chassis clean metal or to battery ground terminal.
Thanks Brett I may do that unless someone answers my question.
I think you can find the King Control ground wire(s) from their wiring diagram, than connect that wire directly to start battery ground. Probably the brake light ground is ok and not your problem.
Do check the brake light switches as this area is very wet and bad grounds there are notorious. I replaced the brake light switches two years ago and used copious amounts of dielectric grease on these connections.
I have replaced the throttle control and it works ok. I didn't drive the coach. I also sprayed the brake switch connections with Corrosion X. After I run a new ground I probably won't know if the problem still exists until after a long drive. Thanks for the replies.
I've been doing some things getting ready for a trip next month. Today decided to go over electrical connections that might be associated with my cruise control problem. Found one loose connection on an air pressure switch, not sure if it is for brake lights. There are 4 air pressure switches near the steering gear box. 2 above the gear box and 2 on the left looking forward. Loose connection was on the left side switch nearest the gear box. Hope that loose connection was the problem, but won't know until I drive it for a few hours. I have not been able to find where the ground is for the brake lights. I had the engine running while checking all the outside lights and discovered that if the high beam lights are on, fast idle will not engage. Low beams or any other position of the headlight switch is okay. Rather puzzling why that would have any effect on fast idle. The turn signal stalk does activate the high beams but the switch for that is in the steering column while the cruise control is in the handle. I plan to see if cruise control will work with high beam on. I never had my lights on with the previous problem. Has any one else experienced this?
Jerry,
I take it that your '96 did not have the Generation 1 Smart wheel. That high beam thing is puzzling but it is a clue as to what the problem may be. Have you looked at the connection is the steering column? I really don't know what that would entail, but the connections there may be an issue to resolve or just exclude as a source of the problem.
I suppose I have a dumb wheel, since it only has a horn button. Yesterday after a little work, I decided to take it for a drive and see if the high beam had any effect on the cruise control. Right away the fast idle function was normal with the high beams on, not like the day before. Cruise control was normal during the drive with high beam on or off. I didn't feel like driving a couple of hours to see if it would continue to work which is the original problem. It gets tired after about 2 hours and refuses to work. Lights on especially high beam cause a voltage drop, so maybe that could have some effect?? But one day and not the next? I've got my drive by rope ready just in case.