79 Mercury 150hp V6 choke not staying engaged upon start position help

[tawas23]

79 Mercury 150hp V6 I am having problems with the electric choke when I press the choke button the butterflies close as suppose to but when I turn key in the start position and hold choke button the choke opens when cranking then closes again after starter is not engaged anymore.. can someone help me in why the choke does this as its not helping start the engine with choke button is used.I have to use starting fluid to start and hold the choke button for a few seconds until warmed up as it works only if starter isn't engaged

 

[Chris1956]

Well, it could be a wiring problem, or a voltage problem. First the wiring problem:

The ign switch is supposed to supply voltage to the accessory pole when in the start position. The acc pole provides power to the choke circuit. Maybe yours was changed to a model that doesn't do that, or maybe your is malfunctioning.

See if the accessory pole gets voltage when in the start position. If so, maybe the voltage drop of the starter deprives the choke of enough voltage to operate. Cleaning the wiring harness could fix that.

 

[444]

Put your multimeter on it and see what it's showing when cranking. It should stay closed properly, I know my 78 175hp would have to be cranked until the battery went dry if the choke didn't work. If you apply 12v from an external source does the solenoid stay closed during cranking?

 

[tawas23]

ok thank you I will check that out today and get back with my readings .I put a new starter on and spins much better as the old starter was dated 12/10/1977 so that was bad drawing to many amps and I also put a new rectifier and starter solenoid on so I will check that choke voltage when in start position next and tell you my findings thanks for the help in the right direction

 

[tawas23]

I replaced the starter solenoid also and still in cranking position choke opens then closes after cranking .tried 2 different batteries that are both less than a year old everything else works as it should except choke staying closed when in start position.. I don't know what or where to check while in crank position not sure what pole you mean to check as battery cable goes to starter solenoid and both have been replaced starter and starter solenoid.. .I not understanding what would cause this to happen would the choke solenoid that closes the choke make this happen even if works and closes fine until my ignition moves to start position..need some ideas plz thanks.if the choke solenoid stops getting power when key is in start position what would cause that to happen..

 

[Chris1956]

Can you put a voltmeter on the choke, take a reading (choke button held down, ign on), and then crank the motor (choke on) and take another reading?

If you get zero voltage on the second reading, I would think the ign switch is the culprit. If you get 8.5 volts (or thereabouts), the wiring or choke solenoid are suspects.

 

[tawas23]

ok I will check that today Chris and reply back thank you for helping me I really appreciate the help ..

 

[tawas23]

OK Chris I just did what you said I put the volt meter on the choke solenoid positive and grounded to battery when I pressed the choke button with key on the volts read 10.75 /11.75 with button pressed choke closes.. then turned key to start position volts shot down to zero so something is shutting off the choke in start position ..where to I check now as not sure what to check next??

 

[Chris1956]

Gee, it sounds like the ign switch is wired wrong, or is malfunctioning. Is this a new boat for you?

 

[tawas23]

yes it is and not sure if its wired correct the color of wires to ignition are red/black/blue/yellow/white if I upload a pic can you direct me in the right direction plz

 

[tawas23]

I did send you my number in a message do you mind calling and helping me out with ignition

 

[Chris1956]

If you put the motor in gear, the neutral interlock should keep the starter solenoid from getting any power.

I would therefore recommend you put the motor in gear and "bump" the key to make sure the starter doesn't engage. With the key turned to the start position, push the choke button and see if the choke works. If so, the ign switch is wired correctly and working correctly, and I would expect some sort of voltage drop in the +12VDC ing power circuit.

If the choke doesn't work, either the ign switch is the wrong one, or defective. You might be able to jumper from the starter solenoid wire to the choke wire, to allow choke operation when starting.

Any idea if the ign switch has been replaced?

 

[tawas23]

yes the owner before me did replace the ignition switch I called and asked him just now .so if I add a wire from stater solenoid to the choke it will stay engaged when start position then I hold the button after starting and that will fix this issue correct being it works fine out of start position correct as everything else does work except t that part correct???

 

[Chris1956]

OK, it sounds like he put the wrong ign switch in.

If you jumper the starter solenoid to the choke solenoid, every time you start the motor (hot or cold), you will be choking it. That is probably not the best way.

It would be better to jumper from the starter solenoid post on the ign switch, to the accessory post on the ign switch. However, you need to see if that truly feeds the choke circuit. The wiring diagram says it does, but one never knows for sure.....

 

[tawas23]

Hey Chris do you think it would be easier to just add a toggle switch to the choke solenoid and the battery then went I flip the switch the choke come on and stays on until I flip the switch in off position and dont use the choke button at all cause its wired on its own switch .would that work to make things easy until I can follow each wire on ignition making sure its wired correctly.will this way be ok until summer over?? .what ignition switch is the correct one for this outboard and I will start fresh with correct switch when time allows??

 

[Chris1956]

Hey, Scratch post 15. If you jumper the acc and sol wires together, the starter solenoid will be powered the whole time the motor is running.

I think it may be easiest to change out the ign switch. You should be able to get them at any marine store. Are you using a MerControl, with the ign switch built-in? If so, the ign switch likely is soldered to the wires. That is a bit more work to change, but is the best fix.

IMO, it would be better to replace the ign switch, than fool around with pulling new wires, a toggle switch etc. The maxrules website has a wiring diagram for your motor, but the wiring colors are different that you describe. You will need a wiring diagram that matches your motor.

Also, do you have the reverse lock solenoid and switch? Any idea if that plays into your issue?