70hp Mariner 3 cyl CD ignition (NO SPARK)

[westexasrepublic]

1979 model,

This is the information leading up to the problem.>

I sold this guy my old boat, which I replaced all the electrical on the motor mentioned, parts replaced.
>new Wiring harness on motor
>3 coils
>switchbox
>trigger
>stator
>plugs and plug wires
>rectifier

after replacing the motor ran strong and started like it should, very strong spark and good compression on all 3 cylinders.

now the problem, The guy lost the only key and instead of getting a used one that fit he took it to a place with no experience and thye wired in a new ignition while still connected to the battery sparks flew (so he said). longer story short, the old ignition is wired back on after sparking the wires a little more and he found a key to fit.....(judge the guy all you want, I did) but he's now paying me to fix it so im trying my best without having to reorder all those electrical parts.

I tested the coils they tested good according to the Seloc manual, I replaced the rectifier after it tested bad (assumed it fried from all the fireworks)....

Now why am I not getting any spark? do the ignition switches fry as easily as rectifiers? and if so, would it still crank the motor just not send a spark?

 

[CharlieB]

Re: 70hp Mariner 3 cyl CD ignition

Re: 70hp Mariner 3 cyl CD ignition

Unfortunately, inexperienced people messing with an outboard ignition often make the $$$$ mistake of connecting the 12 V power to the Black wire with the thin yellow lead (the Ground-to-kill) immediately frying the ignition module.

Disconnect this black w/yellow from the ignition module and retest for spark, if none you should be SURE to test the stator and trigger before spending his money on a new module.

 

[westexasrepublic]

Re: 70hp Mariner 3 cyl CD ignition

Re: 70hp Mariner 3 cyl CD ignition

ok I just got off the phone with him and Im gonna continue to research untill I go back over there next week....

Charlie I will try your advice. However I guess one main question I have right now is......That if the original ignition switch still turns the motor (engages the starter) means that the switch is still good?

#49

 

[CharlieB]

Re: 70hp Mariner 3 cyl CD ignition

Re: 70hp Mariner 3 cyl CD ignition

Yes, and No.

The Ignition switch is two separate switches in the same housing.

The ignition side "grounds-to-Kill', in the Off position it connects the black wire with the thin yellow line to the solid black wire, grounding the ignition module, killing spark. This is the same black w/yellow wire found on the ignition module, disconnecting it here and testing for spark will show a defective ignition side of the switch.

The other portion of the ignition switch is momentary contacts to provide 12 V (Red) to the starter relay (Yellow w/thin red line) for cranking/starting the motor. Cranking the motor does not necessarily mean the ignition side is good.

You can test the ignition side with an Ohm meter, black to black w/yellow should show continuity only in the Off position.

At NO TIME should you ever get a voltage reading on the black w/yellow, battery voltage here WILL FRY the ignition module. Note that this test is done with the motor NOT running. When the motor IS running the ignition module WILL energize this wire, grounding it stops the ignition module from firing the coils, no spark, and the motor dies.

The common error wanna-be boat mechanics make is assuming the outboard ignition is the same as automobiles, they change the ignition switch with a generic switch that ENERGIZES the ignition, thus toasting the ignition module.

Most outboard are an evolution of the old magneto, requiring a 'Ground-to-Kill' switch.

 

[westexasrepublic]

Re: 70hp Mariner 3 cyl CD ignition

Re: 70hp Mariner 3 cyl CD ignition

i searched and found this quote from another thread you helped...I think I understand what you're saying, basically this switch is bad and grounding out confusing the motor, making it think the key is in the "off" position even though its not.

The 'Ignition switch' is actually three switches in one.

Ignition circuit grounds the ignition to kill spark in the Off position, 'opens' these contacts in the 'Run' position to allow the ignition system to function.

Accessory switch, provides 12 V when turned to 'On'(Not on all models)

Start switch provides 12 V to the starter relay when turned to the 'Start' position.

Wires on the backside of the switch:

Red, constant 12 V from the battery side of the starter relay, thru a fuse on the motor, usually near the starter relay.

Black, ground

Black with a thin red line, ignition kill wire.

Yellow, with a thin red line, starter relay, passes thru a starter lock-out switch connected to the shift linkage in the control box, shifter must be in Neutral.

so if I disconnect the Black/yellow wire and crank and also get spark that means I need to replace the igntion switch #49 in the diagram?

 

[jeffersondodson561]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

Have you tried to disconnect the main wiring harness from the motor side (the pronged plug). Then crank over with solenoid, If you do this and you get spark, need a new wiring harness.

 

[westexasrepublic]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

No I havnt tried that yet, but how would I start it removed from the wiring harness? using the pull cord?

 

[CharlieB]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

First, disconnect the kill wire at the ignition module (black w/yellow), if it now sparks then you know your problem is in the kill circuit.

Then reconnect the wire at the ignition module and disconnect it at ot near the ignition switch and retest again. If you still have spark with it disconnected at the switch then yes, replace the ignition switch.

It is also possible that the problem could be at the lanyard kill switch or a short elsewhere in the wiring harness.

 

[westexasrepublic]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

there is no lanyard kill switch on this set up, reference diagram above.

"ignition module" iv never heard that term before, do you have a pic for explanation?

>here is a link to the schematic of the engine im working on,>
http://www.boats.net/parts/search/Merc2/Mariner/70/5361993 THRU 5702219/parts.html

 

[jeffersondodson561]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

You probably need a remote starter switch, sears or harbor frieght jump the high amp to the low amp side of starter solenoid...laymens term with your remote switch put one end on the batt + side of solenoid and the other on the yellow/red small gauge wire of the solenoid this will allow you to crank the motor but if it starts suddenly you will have now way of turning it off so had plug wires removed ready to check spark.

 

[CharlieB]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

Ignition Module = Switchbox

The black rectangular box ON the motor that connects the stator, trigger, and has the three green wires to the coils.

 

[westexasrepublic]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

So last night I went to work on the motor and this is where I am now.....

I found that cranking the motor with the key gives a spark, a very weak orange spark that wont jump from the boot to a bolt on the block like it should if it where strong....

SO

I unhooked the wiring harnes to the motor and tried to string start it, when I noticed a niced bright purple spark!

what gives? bad wiring harness or bad switch? because it will give a str0ng spark with them disconnected

 

[CharlieB]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

Disconnect the Black w/yellow at the ignition switch and retest.

Even a small short in the ignition switch will reduce the spark.

 

[westexasrepublic]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

I replaced the Ignition switch and redid the wire to the switch with a good solid solder job and now we got a nice hot spark!

still wont start, is there a reason im getting fire on all 3 cyl and its still not turning over?...will try again results to follow..

 

[CharlieB]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

Basic troubleshooting to ensure the motor has the three things necessary to run.

Spark. You've done that, however, if someone has been messing with the engine while the ignition switch was bad, they may have screwed witih the timing and carb settings. You may want to connect a timing light and verify timing.

Compression. Test to ensure there is no mechanical problem such as poor ring seal causing low compression.

Fuel. Test fuel pump, clean carbs.

 

[westexasrepublic]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

*********LAST UPDATED FIX**********

i guess since it was sitting for 7 months it was just hard to start, nothing a little starting fluid around the carbs didnt solve. Finally got it fired up, but when we went to put the control box back together I accidently smushed the new switch, so now I have to order another one, but long story short is that it was a bad switch and rectifier that needed to be replaced. So now it runs good as new.

 

[diveritematt]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

Just bought my first boat and i have a similar problem. When i got it it ran good even went with the sellar to a lake and ran it all day. Took it home and parked it, then went to the lake two weeks later and it would not start. Its getting fuel, but no spark. Not sure where to start. I did want to clarify that the switch box is called and ignition module?
diveritematt

 

[CharlieB]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

It's not good to hijack an old thread, read the old thread and follow the steps, it may lead to your solution also, otherwise, start a new thread, spell out your problem, motor, serial, and what you have tried so far to figure it out, we will them advise you how to troubleshoot and repair your motor without spending money on un-necessary parts.

 

[diveritematt]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

Sorry I was not aware of how to use a forum. This is my first time. I was looking up to understand what hijacking a new forum, so I found instructions as well as what is proper etiquette. I now understand what you were talking about. I just saw your username on a lot of talk about this problem. I have already reviewed in depth the things you discussed, but apologize for butting in. I will try to figure out how to start a new forum, but will this mean I would still get you expertise and input into this problem?
Thanks
diveritematt

 

[CharlieB]

Re: 70hp Mariner 3 cyl CD ignition (NO SPARK)

At the top of the listings in the Merc forum, on the left side is a button '+PostNewThread'

Click on that and spell out what you have, what it is doing, or not doing, etc.

Choose your title carefully so to give an idea of the type problem.