possible neutral safety switch issue

oldboat1 · Post by **oldboat1** » Fri Jul 08, 2011 11:25 pm

My cooling issues seem to be resolved with the t.stat and sender replaced. Coming out of the moorage at idle, the temp went up to about 170, but ran the boat (1980 F26, MerCruiser 288 MIE 305) at about 3200 rpms, then backed off to about 2800 which seemed more comfortable. The temp was fine throughout at approx. 140 or even below. I trolled for about a half hour at idle, with the temp steady at about 130 -- think it was good to run it out a little.

But a step forward, and one back. I've periodically had to jiggle the shift lever to get the starter to engage, and figure that is the neutral switch. Tonight, the engine stalled as I was trying to dock - had shifted to neutral, and stalled when I tried to slip it back into forward gear. When out on the water, I had it in neutral a couple of times, and had no issues going back into gear. At the dock, though, I was unable to restart (i.e., reengage the starter). I also noticed that the switch in the "on" position was apparently not sending any current to the gauges. I don't know if that was happening before when I was unable to start without messing with the shift.

So I have questions. Does this sound like a neutral safety switch issue, and if so, where is the switch located? In the shifter housing? I'm thinking I could jump the wires if located at the shifter, and see if the starting circuit is restored (understand I need to be sure the boat is in neutral for this to keep from additional excitement). If anybody has a pic of a MerCruiser shifter switch, that could help.

I would really like to be able to trust this boat, but so far can't quite do it.

Big D · Post by **Big D** » Sat Jul 09, 2011 12:07 am

The neutral safety switch only plays a roll when starting the engine. Once running, that switch is out of the picture otherwise you'd stall every time you shifted gears. Depending on the application, the switch will be in the shifter or at the tranny. The starting issue could be the switch out of adjustment or needing replacement. Cutting out while running is entirely different. If it's a switch issue, it's more likely your ignition switch but other things will also cause stalling when putting her under load.

prowlersfish · Post by **prowlersfish** » Sat Jul 09, 2011 8:01 am

BigD is right on , it sounds like you may have 2 issues . the neutral switch will not cause it to cut out , look for lose wiring at the ignition switch would be the first place I would start try wiggling it around and wiggle the key too .

jddens · Post by **jddens** » Sat Jul 09, 2011 12:06 pm

what rpm does it idle at? Sounds like it could be a carb problem to me.....friend had the exact same symptoms on his house boat and rebuilding the carb fixed it. Sometime it would idle ok and sometime die.....real bitch getting a single engine 43 foot boat in the slip when the engine keeps dying............John

TurboTim · Post by **TurboTim** » Sat Jul 09, 2011 4:05 pm

If you have velvet drives you can jumper switch. It is on Starboard side of trans just aft of the trans mount.

prowlersfish · Post by **prowlersfish** » Sat Jul 09, 2011 7:17 pm

The carb or n/safety switch's will not cause the loss of power to the gages and engine .

oldboat1 · Post by **oldboat1** » Sat Jul 09, 2011 9:15 pm

I think what's really bugging me is that I had similar issues with a '77 Chris Craft (also a 305), and after most of a long summer I finally found a heavily corroded wire harness plug-in connection down in the bilge next to the engine (also a 305, which is probably a coincidence). Rewiring the connection finally took care of the unpredictable engine shutdown issue -- which is really unnerving. This time it happened while I had pretty much nosed into the slip, which was fortunate. But I would really like to be out boating without being on pins and needles.

lots of good info and advice -- thanks. If as suggested the stalling and the failure of the starter switch in the on position aren't related to the neutral safety switch, it sounds like I need to look for an electrical solution to the switch failure first, then go after the neutral safety switch if that remains a problem. (The starting issue with the safety switch has been a periodic annoyance, but the stalling is new -- also the failure of the starter switch in the on position, I think.) The engine idles at about 800 rpms when warm, or maybe a little less, and has seemed to run smoothly and accelerate smoothly in all ranges. It just seems electrical -- a fuse, maybe, or a loose connection at the switch. So I guess I'll proceed with that. Most of the fuses are at the front of the steering station, covered by a keyed wooden door. The main key (red plastic) is also under there, and seems to be under separate cover (black box). I'm not sure where the main starter fuse is (50 amp?), but may be located there. I recall there is a red button, maybe a reset switch of some sort -- may be the solution to the current issue?

Believe it or not, one of the first things I checked for when I looked at the boat was any part of the wire harness in the bilge (like the old Chris Craft). I didn't see any, but you can bet I'll be checking again.

It is a velvet drive in-line transmission, so I'll keep in mind the neutral switch could be jumped there, as suggested. If I can solve the stalling/shutdown issue first, I'm inclined to see how messy it would be to lift off the housing on the controls, to see if there is safety switch wiring (or a contact switch?) there. The engine had been going in and out of forward and reverse without any issues, so I'm guessing the linkage at the transmission is probably OK -- contact point re the neutral safety switch has seemed to be just before the point at which the lever would engage reverse gear, so I had been thinking maybe the adjustment would be in the shift box.

Stalling issues aside, it looks like the neutral safety switch at the transmission should be fairly easy to replace -- would welcome some info on that, just in case.