OMC Electrical Issue, slave solenoid?

[weenmeoff]

Hello,

I am only getting a click when I turn the key on my mid 80's 4 Winns with 4.3 OMC Cobra. I read this post about electrical issues which says OMC has a different kind of slave solenoid, http://forums.iboats.com/forum/engi...hooting-your-engines-starting-system?t=167035

Is the OMC solenoid right next to the dip stick in the picture below? There are only 2 terminals (both appear to have 2 wires attached.) When I touch the test light to the back terminal it lights up and when I touch the front one and turn the key it does not light up. Does this mean my lsave solenoid is bad? If so, it looks like a real pain to loosen the bracket, any tips? Also, I tried jumping between the 2 terminals on the slave solenoid (if that is it) and turned the key and still only got a click.

 

[weenmeoff]

In hopes that I would figure out how to remove the slave solenoid (if that is in fact what it is) I discovered that it was very warm almost hot to the touch so I am guessing it is bad. I was able to figure out how to remove and am off to the parts store. I hope it was my issue and will repost back.

 

[weenmeoff]

no luck - any advice on my original post? Thanks!

 

[bruceb58]

What is your model number? There are too many models in the 80s.

If you have a Cobra, it is often mounted where the console shifter and the lower shifter meet on that bracket.

Looks like this:

 

[vinnie1234]

Put a voltmeter on your battery and note the amount of voltage drop when you attempt to start. If there is less than a volt, your starter isn't getting any juice (ie: wiring, solenoids, connectors, corrosion). If it drops from 12 to say.... 9ish,then you need to remove the starter.

 

[jerryjerry05]

That's NOT a slave solenoid that's the oil pressure sender.
The slave solenoid is in a cluster with the trim/tilt solenoids.
Might be on the shift bracket.
Find the trim pump and follow the lead back to the solenoids.
Then: start with testing the harness and spraying WD in the connections.
Then with a test light, check for power at the solenoid as someone turns the key.
There is a solenoid at the starter too. Test there too.

 

[weenmeoff]

"Touch terminal B on the starter solenoid itself, if the test light lights up, then you have a problem with the starter itself."

The test light did not light up when testing the starter solenoid. I found the slave solenoid and it tested OK. The voltmeter drop was from 12 to 11.8. Does this indicate I must have a problem in one of my connections or wires?

 

[vinnie1234]

2 10ths of a volt means your starter motor is not drawing any power. Go to the starter motor and trace connections back towards the ignition switch with the test light. you will find the problem soon,

 

[weenmeoff]

Thank you guys for your help! I will try to trace it Vinnie.

 

[bruceb58]

This is what I would do. Disconnect the control wire to the slave solenoid and get a jumper and jumper the conrol input to you battery. If the engine turns over, you know that there is a problem between the slave and the ignition switch. If it doesn't, you need to determine if its the slave solenoid or downstream more. Move the jumper to the output of the slave solenoid. If the engine now turns over, the slave solenoid is bad. If it doesn't, you need to investigate the starter.

 

[weenmeoff]

I tried my best to trace back from the starter but the wires get lost. I made some assumptions and tried bruce's suggestions and got nothing. The assumptions I made were the the control wire to the SS was the one with only 1 wire hooked to it (red with yellow stripe), the output of the SS has 3 wires (two of them being solid red) and that I am to hook the jumper up to the positive terminal on the battery. Are those assumptions correct?

I did hit the smaller terminal on the SS and got some different clicking.

 

[vinnie1234]

Maybe an understanding of how the system works and why will help you solve the problem?

The solenoids are there to "step up" power. It would burn out the ignition switch to pass the current straight through it - to the starter. When you turn the key from on to start, power is applied to the slave solenoid "trigger" from the ignition switch. The slave solenoid has a mechanical switch which is powered by a magnet. The magnet moves when you turn the key (as long as power is delivered to the trigger). When the magnetic switch in the solenoid turns on, you hear a click. At this point it connects a stronger power (positive to positive) closing the circuit to the starter solenoid. The starter solenoid works exactly the same way as the slave, and when it triggers it bridges the electrical connection from battery positive to the starter motor. This solenoid also clicks when it engages. At this point a direct high current connection to the starter motor is made, via the starter solenoid. A voltage drop at the battery of 3 volts is normal when this happens.

This is why when you drop from 12 to 11.8 volts, I can tell you that the starter isn't drawing power.

You have 2 solenoids to check power on. Slave and starter. Check that the "trigger" terminal (smaller) is getting power, and also check to see that both sides of the big connector (power flow) on each solenoid are getting power. If you find one that isn't getting power, remove the connector and clean it.

If you are able to identify the starter terminal, you could also use a booster cable to jump the starter.
Whether you use a test light or jumpers it doesn't matter. Whether you check from the starter back or ignition switch forward - it doesnt matter. You need to understand the way that power is delivered and why - then you can make logical assumptions based on what you find.Jumping from the battery is a good way to figure things out y yourself, as you don't need an assistant to turn the key.

Hope that helps.