starter slave solenoid problems?

my starter slave solenoid on my boat was bad. so i replaced it with one from an automotive store. the motor will hardly turn the engine over when the neutral start safety switch wire is connected. if i disconnet the wire the boat will crank fine. why is this? do boats need a specific solenoid?

I've heard that there are boat-specific solenoid's, that are water proof, but it doesn't make much sense to me (as vehicles come into contact with water too). I remember when I was replacing a solenoid on my boat seeing the USCGA insignia on the one I replaced with a car solenoid. The car one worked fine, as a matter of fact I'm still using it. I'm not sure WHY it's doing it, but there MAY be boat specific solenoids.

I believe the only difference should be that the boat solenoid is spark arrested. Meaning it won't spark in the bilge and create a chance for an explosion. Functionally they should be the same. I have always used car parts as well and they work fine.

I was thinking the same thing as Stan.

If I recall correctly, The neutral safety switch doesn't have much to do with the solenoid. When the boat is in gear, the switch opens the circuit coming from the ignition switch. For example, From the battery (+) the wire runs to the ignition switch, then after the ignition switch it runs to the neutral safety switch, then to the solenoid. I guess I'm confused how you're disconnecting the neutral safety switch.

Joshua:

I don't believe that there are boat specific starter solenoids, but there are different types.

The term "solenoid" is applied to two different things, although both are related to the starter. In one case the "solenoid" is physically attached to the started and is what shoves the starter gear into the flywheel in addition to acting as the main relay.

Another use of the term solenoid is simply a relay, which is typically mounted up high on the engine in a not too difficult location to get to.

A common feature of some solenoids is to have a "ballast bypass" feature for the coil. In this setup the actual ignition coil is designed to work on a much lower voltage. When the engine is running and the system voltage gets up to 14 volts the coil would be getting too much voltage and could burn up. To prevent this they put a resistor in series with the coil to reduce the voltage. For starting, when the voltage is very low, the solenoid provides battery voltage past the resistor so that the coil can get enough current to produce a nice hot spark for easy starting.

Another variation in the solenoids is how the key wiring is hooked up. Some provide 12volts to the small terminal on the solenoid and then it goes to ground via the frame of the solenoid. Other's have two terminals, one provides 12 volts and the other provides ground. Unfortunately, the two teminal for the key (+12 and ground) and the ballast bypass look a lot alike, but there is a major differenc in the second terminal: in one case it would be connected to ground, in the other case it would provide 12 volts!

It is possible that the solenoid that you installed was not of the same type and there is now a problem in the wiring. I am a bit confused by what you mean "hardly turn the engine over".

If the starter is cranking the engine very slowly when the neutral safety wire is attached then I would think that there is a short. What amazes me, however, is that the neutral safety wire could carry that much current!

Where does this neutral safety wire connect? To the solenoid?

If it connects to the solenoid then I am guessing that you have the wrong type of solenoid. A possible wiring scheme is that the key switch sends 12volts to the solenoid, and then the other terminal is used to route the "ground" path to the neutral switch, which then grounds it (if it is in neutral) to the transmission.

If that is how it was supposed to be, and you installed a "ballast bypass" type solenoid, then you are shorting out the battery through the neutral switch.

The only thing that surprises me is that the wire to the neutral switch didn't vaporize when you tried to start the engine.....

i appreciate your help. in response to Rod McInnis, I think that you may have something there, but your right I would think that by using the neutral start safety switch as a ground it would burn up the wire. Although in my wiring diagram it does show that after the wire reaches the neutral start safety switch there is another wire that directly grounds out. could i check this by unbolting the solenoid and ungrounding it,and then try to crank the boat? would that work? and again thank you for your help.

Josh,

How old is the boat? Another possibility is that the distributor is stuck/frozen in an advanced position.

the boat is a 1992 ski ray produced by sea ray.

Joshua:

I thought of another point that might provide some validation to my theory:

How are you able to start the boat wiht the neutral safety wire disconnected?

If you are not in neutral then nothing should happen when you turn the key, UNLESS it is as I suspected and the safety switch was intended to provide the ground path for the relay and the relay you put in isn't wired that way.

If my theory is correct: If you unbolt the relay, arrange it so that it is not touching anything "ground", then nothing would happen when you turn the key. This is because the relay you have uses the frame of the relay as ground.

Do you still have the old relay? If you have the old relay and an ohm-meter (Multi-meter) then measure the resistance between the two small terminals. If the relay is a ballast resistor type (as I suspect you have just bought) then there will be NO continuity between the small terminals, but there will be continuity between one of the terminals and the case of the relay.

The other type of relay, which I am betting your boat had, would show continuity between the two small terminals and nothing between either terminal and the frame of the relay.


When you go to buy a new relay here are some key words to look for:

Insulated - is good
Ballast, resistor, bypass - bad.

Good luck
Rod McInnis

thanks ill let you know how it goes. Im going to work on it this weekend.