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Author Topic:   Engine cranks with ignition off
rayblnc posted 03-05-2008 11:43 AM ET (US)   Profile for rayblnc   Send Email to rayblnc  
1963 Whaler, 1995 Evinrude 48SPL.

It has been sitting for a year. We had a new baby, and well, you know what happens with weekend boating under those circumstances. I am trying to get the boat running again, and among other things, I am having this problem:

The engine cranks even with the ignition switched off and the key pulled. Even disconnecting the ignition switch wiring does not prevent this.

The battery is about 2 years old, and I had it partially charged (it was completely dead) with a battery charger (10 amp charger). Leaving the charger attached for a bit more power, I cranked the engine a few times, and although the engine didn't catch, turning the switch back off stopped the engine from cranking. Well, after trying to start the motor a few times, it gets stuck on cranking, even after pulling the key. This happened on Sunday. I worked on it again yesterday, and same thing --cranks fine a few cycles and shuts off when the key is turned back to the off position but then stays cranking. It cranks weakly a bit and then the internal breaker on the charger snaps off. After about a minute, the charger snaps on again and the engine starts cranking-even with the ignition switch completely removed.

Any ideas?

Buckda posted 03-05-2008 12:21 PM ET (US)     Profile for Buckda  Send Email to Buckda     
Sounds like a stuck solenoid. I had a similar problem with my 1986 Mercury 150 a few years ago before I repowered.

Take the cowling off and gently tap the starter motor solenoid with a hammer. The solenoid is sticking open in the "crank" setting.

As you know, a solenoid is electro-mechanical. The hammer will help disengage the soleniod.

If this works, simply replace the solenoid (about $20 for the part and about 10 minutes for the labor). It has two wires and will be attached to the powerhead, likely near the starter motor (Check your service manual).

Good luck.


rayblnc posted 03-05-2008 01:38 PM ET (US)     Profile for rayblnc  Send Email to rayblnc     
"Sounds like a stuck solenoid."

Thanks, just picked one up at the local BoatUS during lunch hour here. I had a feeling it could be the low/high voltage switch last night, but looking at the Seloc manual didn't turn anything up in the index. For some reason my brain was stuck on the word "relay".

Cheers and thanks,

contender posted 03-05-2008 03:49 PM ET (US)     Profile for contender  Send Email to contender     
Could also be the starter, had this happen on a car I had one time. Had to run around and disconnect the battery to stop it from turning over. Check the solenoid first its easy and cheaper, but then I would pull the starter and have it checked...good luck
Chuck Tribolet posted 03-05-2008 05:44 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
I'd hit the solenoid with the butt end of mid-sized screwdriver.
A hammer would be overkill.

I don't see how it could be the starter. If the solenoid is
working right, the starter has no power and can't turn over.


Buckda posted 03-05-2008 05:51 PM ET (US)     Profile for Buckda  Send Email to Buckda     
gently tap the starter motor solenoid with a hammer

Using the butt end of a screwdriver is fine too....that's about the impact level I was trying to describe above - a gentle tap rather than "hit it with a hammer".


rayblnc posted 03-05-2008 07:54 PM ET (US)     Profile for rayblnc  Send Email to rayblnc     
Ummm. Hehe.

I tried to reconnect the ignition switch.. and I don't know if I got it straight the first time. I get no power anywhere now. Could I have blown something like a fuse?


rayblnc posted 03-05-2008 08:22 PM ET (US)     Profile for rayblnc  Send Email to rayblnc     
Let me add to that. Since I didn't have a diagram, I figured I could I identify which pair did what with a jumper, then attach to the ignition switch. I have a sinking feeling that this was not a good idea. :-(


Buckda posted 03-05-2008 08:26 PM ET (US)     Profile for Buckda  Send Email to Buckda     
It is likely you fried a fuse. I'd check all in-line fuses...if it is for the starter circuit, it is going to be a pretty big (read: expensive) fuse. Try not to do that again!

Get a manual that shows the wiring diagram. Best $50 you will spend on that motor.


Jerry Townsend posted 03-05-2008 10:44 PM ET (US)     Profile for Jerry Townsend  Send Email to Jerry Townsend     
The starter cables from the battery to the solenoid and from the solenoid to the starter are not fused. Certainly, if they were fused, the fuses would be LARGE.

Let's see - 1 hp is equivalent to about 746 watts and with our 12 volt power, means about 62 amps/StarterMotorHP. That is the current required to RUN a 1 hp starter motor. STARTING the starter motor will take what? - maybe at least 50% more - or somewhere around 93 amps. Of course, these are for short periods of time, but that is why typically 2 - 3 gauge wire is used with no fuses. ----- Jerry/Idaho

jimh posted 03-05-2008 11:29 PM ET (US)     Profile for jimh  Send Email to jimh     
I don't think there is any starter motor malfunction which could result in the starter motor powering itself. Electrical current to the starter motor is controlled by a special type of high-current relay called a solenoid. If the starter motor is always running there are only two reasonable causes:

--the solenoid high current contacts have fused and the solenoid supplies current to the starter regardless if its coil is energized or not, or

--there is malfunction in the solenoid coil circuit and it is being supplied with current, energizing the solenoid.

In order to diagnose and repair electrical problems you have to have:

--a good multi-meter that can measure resistance, voltage, and possibly current, and;

--an understanding of the basic principals of electricity

Chuck Tribolet posted 03-06-2008 09:14 AM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Get the FACTORY service manual. The aftermarket manuals tend
to be a lot of one size fits none text.

If you can get things failing again, pull the small wire off
the solenoid. If it keep cranking when the wire come off,
it's a stuck solenoid. If it stops, the problem is in the
wiring or switch.


rayblnc posted 03-06-2008 07:40 PM ET (US)     Profile for rayblnc  Send Email to rayblnc     
OK here is the scoop. I got her running today! The engine ran great, even after a year of sitting. I got the wiring figured out with the help of the diagram on this site. It was a little weird because the difference between the two "M"s on the ignition switch were not obvious and the switch had an "A" AS WELL as an "I", so not standard at all. Some say the starter motor does not have a fuse, maybe not, but the starter motor solenoid does. It is 20amp, and it was blown. I replaced that, wired the ignition switch, made sure the battery had a full charge (I need to replace it, got her cranked up and she ran like a champ! There are some minor issues I need to clear. A couple of wires for nav lights and the fish finder are pulled out but that is easy. I also have not installed the new starter solenoid, but something makes me think that sitting for a year in the humid Florida climate made it sticky and that use should get it doing its thing again.

One more question, I have the habit, after using the boat, of not only flushing the motor but also removing the cowling and coating everything in their with a light even coat of WD-40. I've always done this. Is this a good practice?

Thanks to all of you for the help. Can't wait to take the family for a cruise in a few weeks.


Jerry Townsend posted 03-07-2008 12:07 PM ET (US)     Profile for Jerry Townsend  Send Email to Jerry Townsend     
rayblnc - the blown fuse on the starter solenoid coil blew for a reason - something shorted within the solenoid. A solenoid is very a simple device - just a coil of wire that is basically just a big switch - for the large current required of the starter motor. One should have extra fuses in the tool-box - but, if it were mine and since that engine can not be started without the starter operatable (unless it can be pull-rope started) - I would replace the solenoid. They are not all that expensive - and it could eliminate an unpleasant experience. --- Jerry/Idaho
contender posted 03-07-2008 12:31 PM ET (US)     Profile for contender  Send Email to contender     
wd-40 is not bad (at least you are doing something) but after a while it leaves a dark brown mess (cooks on your engine probably from the heat of the engine) Look at another product/products CRC, 3M, Blaster, Blue Bloc etc, ...good luck
Chuck Tribolet posted 03-07-2008 01:11 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
The fuse could be blown due to a miswiring that's since been fixed.


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