2000 Marquis won’t start at keyswitch but will at rear start

[Dwayne Bratcher]

Our ignition switch won’t start our coach. Powers up but no crank. After checking the usual suspects many other owners have found, discovered a wire connection broken at the “rear/kill/front” selector switch. The coach would start fine from there but could not shut it down at rear kill, only ignition switch. Fixed the disconnected wire and still wouldn’t start from ignition. After several other things I returned to decided to start the coach from rear switch just to make sure everything I had done past few days had not changed anything. Turned ignition key on, walked to selector switch and chose “rear” and hit the start button. Fired right up. Hit the kill switch and tried it. Engine shut down. Flipped back to front and turned the key, coach started at ignition switch. So if you have this issue, remember to cycle the rear start switch. Makes all the difference!

[Fred Brooks]

   Dwayne,
 The 2 weakest links on a 27 year old Marquis start sequence are the Ignition run solenoid in the electrical compartment under the driver's window. (see picture) and the Ignition switch itself. The switch is a Delco-Remy early 70's Chevrolet pick-up truck. Concerning the rear run switch, let me share my experience with you. Normally this switch is rarely used and it is located in a hostile envoirment. I have found that if the switch is used it either creates a new issue or solves another. I believe the contacts inside the switches are either corroded or dust covered from lack of use. Hard to say, almost all of us carry a spare solenoid and ignition switch as they will fail. A common theory about the ignition switch is an excessive amount of weight from too many keys on the key ring cause an internal issue inside the switch? Hope this helps, Fred