Negative Polarity. Help

Dunham78

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Mar 23, 2020
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Thanks ****. I do appreciate the help. I’m just stupid when it comes to electrical ****. And do really understand it. I wanna get in my boat and get a line wet, no mess with this thing. But with that being said, I’m also a poor bastards.
 

oldboat1

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Charge up the battery and clean connections until shiny. Concentrate on starter cranking flywheel at about 250-300 rpm (fast). Check spark after you are sure the starter system is working properly.
 

Dunham78

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Ok, FR I do honestly appreciate the help. The wiring digram was very helpful. Hopefully this is my last question. And it may be stupid. So I followed 12v to from the battery to the starter, then from there to terminal block. As I’m following my wires to my ignition I have 12 v before my plug going towards key, I got 12v after plug. But don’t have 12v on red wire at my key. Could not having 12v there be causing my issues?
 

achris

More fish than mountain goat
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Ok, FR I do honestly appreciate the help. The wiring diagram was very helpful. Hopefully this is my last question. And it may be stupid. So I followed 12v to from the battery to the starter, then from there to terminal block. As I’m following my wires to my ignition I have 12 v before my plug going towards key, I got 12v after plug. But don’t have 12v on red wire at my key. Could not having 12v there be causing my issues?

If the engine is cranking, you have 12v at the key. The starting system and the ignition system only ever come together at the negative post of the battery. Deal with them as 2 completely separate systems.

The power pack is powered by the stator (a simple coil of wire) under the flywheel (which has magnets on it). It only gets power once the flywheel is spinning (at a minimum of 300rpm). Any coil of wire that is being 'cut' by a magnetic field will generate a current. That charges up the power pack (or at least a capacitor inside the pack). Also under the flywheel is a 'trigger', that pulses the power pack to fire one coil or the other (using the same principles of magnetic fields and coils of wire). There is NOTHING in the ignition system that is connected to the battery in any way. Although not in any way recommended, but you could remove the battery completely, and using a pull cord, start the engine and it would run perfectly without a battery.

It's highly unlikely that reversing the battery damaged the power pack, as that 'kill' wire has over 300v on it when the engine is running (ask any marine mechanic how they know that. ;)) Reversing the battery and putting 12v on the kill wire will do NOTHING to the pack.

The only thing you will have killed is the rectifier, and that's already been dealt with by the suggestion of a simple bridge rectifier from Tandy. The rectifier in the engine would have originally been rated at about 6 amps, this one is 35 amps. The only thing that will kill that is corrosion (and reversing the battery again. Buy 2)...

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What are you touching on the power pack that is giving you a spark? (When the engine isn't running, every wire on the pack should be dead)

Chris.......
 

Dunham78

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Mar 23, 2020
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Chris,
Thanks for that response. When I 1st started tinkering with this. The 7 slot on the power pack, when touched with test light would spark just a bit and the motor would almost pop, like backfire. I did that once. I was told to check for fire at the power pack by holding test light to number 2 and 3 slots while cranking motor. Never saw anything there. I checked the ohms on the Stator and it appears to be ok. I’ve cleaned every ground and every wire lead. Charges battery fully so I got good cranking power.
 

F_R

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28,226
#7 is one of the sensor leads, You MIGHT have triggered one of the SCR's in the power pack, causing it to discharge any residual charge in the capacitor to one of the coils. This is pure speculation.
 

achris

More fish than mountain goat
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The timer ('trigger' is what most people would call it) is like the stator, just a coil of wire. Measure the resistance on it. Between both wires, and from each wire to ground. Been a while since I worked on these, I think the trigger produces an AC wave, and the spark for one cylinder is on the positive side of the wave and for the other on the negative side.

Chris......
 

Dunham78

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Mar 23, 2020
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Thanks for all the help. And my apologies for anyone I offended. It turned out it was the trigger. I got it replaced and she’s purring like a kitten. Thanks again. Best Regards
Zack
 

achris

More fish than mountain goat
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Thanks for all the help. And my apologies for anyone I offended. It turned out it was the trigger. I got it replaced and she’s purring like a kitten. Thanks again. Best Regards
Zack

That's great, but you reversing the battery did not damage the trigger, it can't. Just one of those things.
 

Doh

Petty Officer 2nd Class
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Aug 12, 2008
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193
First off, I have made the same mistake before. So don't feel Bad.

When I did, My fuse blew immediately, Replacing the Fuse, everything was good.

Your issue on the other hand, is different. I would tend to believe that the Power Pack, suffered from the mistake.

If it cranks, then the Fuse is good. A Rectifier, only changes the Lighting Coil's AC Voltage to 12-13v DC, to charge the battery and not the Ignition circuit, that is handled by the Trigger Coil.
 

Faztbullet

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"It's highly unlikely that reversing the battery damaged the power pack, as that 'kill' wire has over 300v on it when the engine is running (ask any marine mechanic how they know that.

;)
) Reversing the battery and putting 12v on the kill wire will do NOTHING to the pack."

Have to disagee with ths as seen many packs damaged by old defective keyswitches, below is from CDI test guide

Note: If CD-77 is used for DVA, you will need a good volt/ohm meter.
NOTICE: Initial DVA readings should be taken with everything hooked up.
1) Check the flywheel for cracked and lose magnets.
2) Disconnect the kill wire(s) from the pack and retest.
Connect a DC voltmeter between the kill wires and engine ground. Turn the Ignition switch on and off several times. If at any time, you se DC voltage appearing on the meter, there is a problem in the battery Harness or the Ignition switch. NOTE: At no time should you see battery voltage on any kill wire




Troubleshooting OMC Power Packs and CD's
Recommended Tools:
for DVA:Fluke Multimeter with CDI #511-9773 Peak Adapter, (or CDI #511-9770 Piercing Probes
CDI #5119-710 Trigger tester (for use with '88-'96 V8, V8 Quick Start timer Bases
CDI #511-9766 Spark Gap Tester
CDI #553-2697, 553-2698, 553-2699 Pin Removal and Insertion Tools
CDI #553-9702 Gap Gauge
Jumper wire
Note: If CD-77 is used for DVA, you will need a good volt/ohm meter.
NOTICE: Initial DVA readings should be taken with everything hooked up.
1) Check the flywheel for cracked and lose magnets.
2) Disconnect the kill wire(s) from the pack and retest.
Connect a DC voltmeter between the kill wires and engine ground. Turn the Ignition switch on and off several times. If at any time, you se DC voltage appearing on the meter, there is a problem in the battery Harness or the Ignition switch. NOTE: At no time should you see battery voltage on any kill wire
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Have to disagee with ths as seen many packs damaged by old defective keyswitches, below is from CDI test guide

Have to disagree with you on this. My first job at the first shop to employ me as a marine mechanic was to go to every outboard-powered boat in the yard and replace the rectifier. One of the salesmen had asked which way around the cables go on the batteries. The (moron) apprentice, as a joke, told him red cable goes to negative, black to positive. So that's what he did, to over 50 boats in the yard, mostly outboards. Blew every rectifier (as expected) and not one single pack.... I got the job of replacing rectifiers, and starting the engines to make sure that was the only damage, so I speak from first hand experience. I'm also an electronics technician with 15 years fixing computers (proper 'size of a building' computers, not these toys they have now). When I was doing the OMC outboard technician's course, the instructor pulled the circuit diagram for the (at the time) latest power packs with the new S.L.O.W. feature, and asked me to explain how it worked.

So, I don't give 2 s... what CDI publish on their website, I've seen the actual circuit diagrams (to the point of reading it, understanding and explaining it to someone else), and I'm telling you, reversing the battery CAN NOT kill a pack, it's just not possible.

Chris....
 
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F_R

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Jul 7, 2006
Messages
28,226
Chris, I 100% agree with you, concerning the battery issue, So what is your opinion on the issue of a defective hey switch damaging the pack by sending 12V to the black/yellow wire? That seems to be what CDi was saying. Or for that matter, possibly sending 12V to black/yellow by some other means, such as shorted wires in the harness or by somebody "fixing" it?

Also, has the kill circuit been change since introduction? I'm aware that, originally, 300V was sent to the ign switch. Has that been changd? Without thinking too much about it, maybe now the kill is by triggering a transistor or something like that??

signed, Inquiring mind.
 

Faztbullet

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Mar 2, 2008
Messages
15,933
. Blew every rectifier (as expected) and not one single pack...
But they were not cranked to see if would start either as poster did..I have seen 6-8 V on the blk/yel from switches damaged/kill packs. We will just have to disagree...I also went to OMC school in Morrow and
Waukegan
 

achris

More fish than mountain goat
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May 19, 2004
Messages
27,468
Chris, I 100% agree with you, concerning the battery issue, So what is your opinion on the issue of a defective hey switch damaging the pack by sending 12V to the black/yellow wire? That seems to be what CDi was saying. Or for that matter, possibly sending 12V to black/yellow by some other means, such as shorted wires in the harness or by somebody "fixing" it?

The kill wire seeing 12v on it will do absolutely nothing. When the engine is running, that wire has 300v on it. That wire being connected to ground, by the key switch, is how the engine is stopped. That 300v is originally form the stator charge coils under the flywheel. That is AC and is then rectified and charges a capacitor inside the pack. The capacitor is used to fire the coil when an SCR gets turned on by the voltage from the trigger coil. When the key grounds the kill wire (black/yellow) the 300v gets dumped to ground, so there's nothing in the capacitor when the SCR fires... no spark, engine stops. The circuit components around the SCR and the kill wire see 300v all the time the engine is running, putting 12v on them is less than a pin prick.

Also, has the kill circuit been change since introduction? I'm aware that, originally, 300V was sent to the ign switch. Has that been changd? Without thinking too much about it, maybe now the kill is by triggering a transistor or something like that??

signed, Inquiring mind.

Last 20 years has seen very different engine ignition systems. The above no longer applies, as most ignition systems are now back to being battery powered, and the spark is stopped by turning off the module. Reversing battery cables on these engines is most likely to completely destroy the ECU.

But they were not cranked to see if would start either as poster did..I have seen 6-8 V on the blk/yel from switches damaged/kill packs. We will just have to disagree...I also went to OMC school in Morrow and
Waukegan

The OP did try to crank the engine, but discovered the starter was spinning the wrong way. That's how he found the battery cables reversed. Spinning the starter backwards would mean the bendix would not have been thrown up the screw to engage the flywheel. The starter was spun, but the engine was not. So, yes, we'll have to disagree on this one.

Chris......
 
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