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Starter solenoid Question

S

Steve Diomin

Contributing Member
I have a 1998 Crownline 5.ol Merc. It has approx 250hrs. My question is that where the solenoid is on he starter motor, there is a purple/yellow wire just hanging there. There is no bare or empty redily availabl post on the solenoid to except this wire but can it be put on th epost where the red/yellow wire is currently?...........I beleive the correct solenoid for this starter would have an available post for this wire but I beleive the previous owners mechanic put this solenoid in place to get him out of a jam for the time being. But as time has passed I think I want that purple/yellow wire to be atached as I beleive it has a function that I need.

What do you think.

Thanks
 
That wire is supposed to provide 12 for starting only and is wired to the starter solenoid`s outboard lug. most engines seem fine without it but all you need to do is replace the solenoid with the correct one.DO NOT CONNECT IT to the other lug
 
how do i know which terminal to connect the purple/yellow wire too? I will attach a wiring diagram of my system. Well i guess i cant as it says the file is to big.
Thanks
 
The wire is not used.

When point ignitions were used the purple/yellow wire was attached to the (I) post on the solenoid and transfered 12 volts during cranking to the coil.

With todays ignitions Thunderbolt IV V etc. that function is done at the ignition switch.........
 
The reason i ask is because I am having a problem with my oil pressure gauge. Tested the gauge, it works, tested the oil sender it is ok. So i have seen that the purple/yelow wire runs into the ol switch somehow on one side, and on the other end ( or another part of this wire) it is just sitting loose at the solenoid like it wants to go somewhere and was hoping that connecting this wire would solve my oil gauge not working...........The wiring diagram also confirms this but i cant make out clear enough which post on the solenoid this purple/yellow eire ataches too.
 
The oil pressure switch and the oil pressure sender are two different circuts!!!!

The oil pressure switch allows the fuel pump to turn on when adaquet oil pressure is sensed during cranking the engine to start, it closes the switch and alows 12 volts to the fuel pump.

The sender is nothing more than a variable resistor. The guage in the dash if it is a stand alone guage is powered by the run (purple) wire when the key is in the on/run position. If you have a efi or newer style it may vary.

When you turn the key to the run position the guage gets energized, when the engine is producing oil pressure the resistance change at the sender should reflect in needle movement.

There are several purple with yellow wires all connected together in the harness and some may not be used.

What schematic are you using?

Can you post it?
 
The file is saying it is too big to post. its 274kb. I realize that the oil pressure switch and the sender unit are 2 diferent circuits but i was grasping hoping that they had something to do with each other as my oil pressure gauge does not work. I have 12v to the back of the gauge, and have had the gauge tested on the bench to get deflection so i know the gauge is good , the oil sender checks out at 240ohms and the blue wire from the sender to the gauge is nice and in tact so i am stumped. Every other gauge flinches when you turn the key excpet the oil pressure gauge. The wiring diagram shows this purple/yellow wire being connected to the solenoid and on my boat it is just dangling riht beside the solenoid. ...............In the meantime i wil try and post the wiring diagram.
 
I just reviewed my schematics,

NO PURPLE WITH YELLOW!!!!! that was used as a BALLAST BYPASS when points were used.

You are using SELOC, FIRST MISTAKE! I am using MERC MANUALS.......


Try ringing out the wire going to the sender to the guage, of course you must remove it from the guage and sender to do this.

Is it possible you have more than one one near the oil pressure sender IE a low pressure alarm??? most likely same color just a different connection........

Is your boat EFI, Carb, thunderbolt IV, V ??????
 
Ok I was wrong.....

Your schematic is correct. What that connection does is supply 12 voolts when cranking to the fuel pump.

I guess they decided that waiting for oil pressure during start up was not a good thing.

If your solenoid does not have that terminal on it then the power to the fuelk pump goes thru the run position on the ign switch but it most likely is dependent on the oil pressure SWITCH.........

Does that make sense???
 
i cant remember if i already posted this part but here goes..............Last year my starter went. A friend who knows more of what hes doing put a new starter/solenoid in to "get me going" to say...........i dont beleive it is the 100% right solenoid he put in as he also knew this but it was to get me in the water right. At about the same time/shortly after is when i noticed the oil presure gauge was not responding. There is an extra post on the solenoid kind of spliced off of the yellow/red wire terminal, but when i touch the purple/yellow wire to this post i get spark so i am going to assume this purple/yelow wire should not go there!............so i guess my question still remains, looking at that wiring diagram can the purple/yellow wire be hooked on to an exisitng terminal on this solenoid or do i need the factory correct solenoid which may have the apropriate terminal for the yellow/purple wire. You see the wiring diagram isnt clear of where each wire connects it just kind of shows all the wires going to to the solenoid.
 
Steve I got your PM and here is your answer.


The large stud on the solenoid, RED (battery), ORANGE (altenator), RED w/purple ( 12vdc supply for the slave solenoid, and the large breaker with the red push button).
This Large stud on the starter is also the main +12 VDC distribution point. This is where it all begins...

The S (small stud) gets the YELLOW/red wire ( this is the wire from the key switch that feeds both the slave and starter solenoids when the key is in the "cranking position)

The I (small stud) gets the purple with yellow, this is the power to the fuel pump during the cranking of the engine.
 
thanks alot, i got it going. Turned out i put the wiring back as i took it off with the yellow.red wire going on the small post furthest from the engine, but on this new oem starter the yellow/red went on the small post closest to the engine. Ther were no markings or anything on the starter. Thanks again.
 
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