Hello all! I ran into strange problem with my 2000 268 Vista (7.4 Volvo DP) during my last trip of the season. It left my mechanic scratching his head and me looking for a new shop to service my boat. I had just motored under shade-cliff to "bob" around while eating lunch. I reached down and switched off the ignition...nothing.
The engine continued to idle. I cycled the switch several times with the same results. I decided to head for open water and home. While cruising, I bumped the throttle up to nearly wide open. When I did that, the engine started to miss, kind of like it was starving for fuel at a high RPM. I glanced down and noticed that I had left the ignition switch in the off position. As soon as I switched it to the on position, the engine ran just fine. Strange. Fearing bigger troubles, I quickly headed to the marina and trailered the boat. Only one problem, I couldn't turn off the engine. Gritting my teeth, I quickly engaged the starter and returned key to the off position. The engine sputtered to a stop. I suspected a bad ignition switch or a grounding issue. I pulled the boat home. I inspected the battery cables and connections; all looked perfect. I then replaced the ignition switch, started the engine and tried again. Yet again, the engine would not turn off. I called my mechanic. He came out and inspected the wiring under the dash, confirmed my new ignition switch installation, double checked the batteries and cables and told me he had no idea what the problem was. I said gee, thanks. He said ..."no problem, no charge for this one. Try a shop that specializes in electrical repairs and good luck!!..." Any ideas out there?
Lesson learned? An experienced mechanic is worth the extra hourly expense. Can save you a wad in the long run.