1999 mercury 90 hp no fire

[jeff t]

was running put in gear and died no fire<br />checked kill switch and key<br />what now

 

[Laddies]

Re: 1999 mercury 90 hp no fire

Disconnect the Blk/yellow wire from the harness and ck for fire

 

[rodbolt]

Re: 1999 mercury 90 hp no fire

check the resistance and output of the stator charge coils.<br /> what color is the stator? does this unit have 3 CDM's or a switch box? if the stator is red do you have the small rectangular adapter module? <br /> its all a matter of inputs and outputs.<br /> nothing in equals nothing out.

 

[jeff t]

Re: 1999 mercury 90 hp no fire

Originally posted by rodbolt:<br /> check the resistance and output of the stator charge coils.<br /> what color is the stator? does this unit have 3 CDM's or a switch box? if the stator is red do you have the small rectangular adapter module? <br /> its all a matter of inputs and outputs.<br /> nothing in equals nothing out.

 

[jeff t]

Re: 1999 mercury 90 hp no fire

stator is red<br />what are cdm's<br />wires from the stator go to a 3x3 solid state box assume that is adapter module<br />checked output of stator with volt meter and it was negative did not check resistance yet

 

[rodbolt]

Re: 1999 mercury 90 hp no fire

ya cannot check output with a standard multimeter, you have to use a DVA meter or a DVM with a DVA adapter.<br /> what wire colors go to that box? the adapter,if used, will be a 1.5"by about 4" box with two wires in and one out.<br /> what I am trying to determine is which ign system you have, merc did not and has not ever Identified systems by year model, strictly seriel numbers.<br /> the CDM type system is a stator feeding indiviual coil/switchbox assemblies the standard system of old AD type was a stator that fed ac voltage to a switch box were it was rectified and stored until the correct trigger signal discharged the capacitor. the CDM will look like a coil only it has a 4 wire connector on each one.<br /> you also will need to test the trigger if the stator tests ok.

 

[andy6374]

Re: 1999 mercury 90 hp no fire

Make sure the coils are grounded properly. This is easy to miss and has fooled me more than once.

 

[jeff t]

Re: 1999 mercury 90 hp no fire

og922654 is the seriel<br /><br />it must be a cdm <br />looks like what you desribe<br />what does DVA stand for? I have a Blue Point multimeter tester

 

[jeff t]

Re: 1999 mercury 90 hp no fire

og922654 is the seriel<br /><br />it must be a cdm <br />looks like what you desribe<br />what does DVA stand for? I have a Blue Point multimeter tester

 

[rodbolt]

Re: 1999 mercury 90 hp no fire

have you checkrd the stator resistance? DVA is a direct voltage adapter. most meters take an average AC reading. we need the peak of the ac not the average. check between the white green to green white stator wires. should see 500-700 ohms. disconnect all black/yellow wires and retest spark. if still no spark disconnect the cdm's one at a time and retest each time.<br /> this system is funny in that a bad kill circuit in one module can take the others out, thats why you need a spark tester on all 3 at the same time.

 

[jeff t]

Re: 1999 mercury 90 hp no fire

no I have not checked resistance yet<br />printing all of this info so when i go work on it I have more to test and not just look at it and wait for it to tell me what hurts

 

[rodbolt]

Re: 1999 mercury 90 hp no fire

hahahaha<br /> I have used that method a few times, it goes faster with a cool refreshing beverage <br />works about as well as renaming the parts

 

[Laddies]

Re: 1999 mercury 90 hp no fire

Jeff your engine is CDM ign. Its quite easy to trouble shoot with no fire at all. The engine must spin at more than 250 RPM with the starter.<br />1. disconnect the blk/yellow kill wires from the harness and ck for spark, this will tell if the trouble is in the kill circurt.<br />2. disconnect the CDM modules 1 at a time and ck for spark each time, 1 bad module will keep the others from firing, if you have fire with 1 disconnected then replace that CDM.<br />3. disconnect the yellow wires from the stator to the reg/rectifier, if you have spark its the rectifier thats bad<br />4. ck the stator white/grn to green/white 500 to 700 OHMs or 18o volts with a DVA<br />Hope this helps--Bob

 

[jeff t]

Re: 1999 mercury 90 hp no fire

hey gus I checked the volts with a meter that records highs and lows on volts I GOT 115 ON THE HIGH.<br />I also did theother things tht you said and none of them worked this seems to lead to the stator being bad if my meter is reading 115<br /><br />do I go and buy the stator now if so any place you sugjest for the best deal

 

[rodbolt]

Re: 1999 mercury 90 hp no fire

lows and highs are not peak voltage, ya cannot get a peak reading with a standard voltmeter unless it has a DVA setting or adapter. by the fact your getting anything leads me to belive your stator does not have an open winding, while your metering shift to the Ohms scale and have a look at the resistance, also check each stator lead to ground,<br /> but without the DVA or a CD-77 type meter any readings you get are flawed and cannot really be used as a test.<br /> the CDM's will actually produce spark all the way down to about 65Vpeak.<br /> the stator is producing ac voltage, however we are usining it to charge capacitors not power a fan, thats why we need peak voltage and not RMS or average.<br /> you can get a rough estimate by multipling the average voltage that most meters use by 1.414 and get a reasonably close measurement of peak for this purpose.<br /> if your stator was open circuited, normal failure, your meter would read nothing out, if one leg was shorted to ground you may see the signal but the ecm would not see the correct signal. thats why a short to ground test is essential on a two wire non grounded coil.