Mercury 6.2 ECT DTS Axius Voltage Issue

[Lou C]

Hey, I've got that same timing light. Customer bought it and gave it to me after he "moved" my much more expensive one so it got into the spinning belts. I felt that I was partially to blame, so I never said anything to him. But I did start enforcing a new rule ---- customers are allowed to watch but must stay at least 6' away at all times.

If you look closely at mine you can see the end made contact with a crank pulley as well but I can’t blame anyone for that one lol. I think the last car I used that on was my 1980 Honda Civic 1300!

 

[tpenfield]

Ted, I seem to remember the last go around with low voltage. But I can't remember if I saved all the files and notes. Can you post or PM your serial numbers? That's how I usually save that info. Also so can you post a link to that thread. If I remember right you stopped the troubleshooting process because new batts or something else seemed to fix it?
I'm pretty sure the relay buzzing is a low voltage issue.

thanks @muc

Engine serial number are below in my sig. 2A458510

 

[Scott Danforth]

As near as I can tell --- you can only drink grog

Both room temp grog and Teds whiteclaws will get you drunk

 

[cyclops222]

Lou Put the gun away.

 

[nola mike]

Hey, I've got that same timing light.

I used to have it. Sadly broke a couple of years ago. Easier and cheaper to buy a fancy one than to try to track down a bulb

I have a feeling that there is a bad connection (or a short) somewhere that is dragging the voltage down from the 12.8 range to the 9.2 range. But once the engine is going the power circuitry is getting enough voltage/current from elsewhere to compensate.

How are you accounting for the relay being powered when it shouldn't be?

 

[tpenfield]

Both room temp grog and Teds whiteclaws will get you drunk

Omission . . .

 

[Scott Danforth]

Omission . . .

There is a provisioning pic from 3 years ago where you had 4 cases of whiteclaw.

 

[tpenfield]

There is a provisioning pic from 3 years ago where you had 4 cases of whiteclaw.

Those were OPD's (other people's drinks)

Here is an updated photo from today. The admiral insisted that I stock up for the summer.

 

[tpenfield]

Diverting back on topic . . . I have mapped the power wires (as best I could) from the overly busy wiring diagram.

Not sure it will upload properly, but here it is . . . I took some liberties with the color designation, since my graphic software doesn't know about wire stripes.
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I believe that I found an error in the diagram reference in the area of the coil packs, so I'm not sure if the #45 item is the 'Throttle Demand' or not. The manual has one of the coil packs referenced as the throttle demand . . .

Anyway, I'll be going through this over the next few days, but I did want to post it for those that may see something. I assume the the VesselView and OBD-M (Diacom) readouts are coming from the connections at PCM-A and PCM-C . . . not sure which one(s) relate to 'system voltage' and 'battery voltage' on the Diacom screen.

 

[cyclops222]

tpenfeld
Have you phoned the manufacturer to see if they made a error and now have a good correction ? I have sometimes got lucky that way.

 

[tpenfield]

Quick Update . . .

Alternator wire is Orange (verified) @Fun Times

I found my 9.2 volts . . . Purple wire on the OBD-M fuse socket (2 amp fuse). I'm now updating my diagram to show the purple wire (aka ignition wire in most cases)

The buzzing of the MPR ONLY happens if I have turned on the ignition for a while , turn it off and then turn that battery switch off. Voltage at the back of the engine then goes from battery voltage down to the 5-7 volt range. When the voltage is at around 5.5 volts the MRP buzzes . . . does that for a while, then the voltage drifts upwards to 6.5-7.2 volt range and buzzing stops. If I turn the battery switch back on the voltage immediately goes back to battery voltage and the buzzing stops.

 

[Fun Times]

Quick Update . . .

Alternator wire is Orange (verified) @Fun Times

I found my 9.2 volts . . . Purple wire on the OBD-M fuse socket (2 amp fuse). I'm now updating my diagram to show the purple wire (aka ignition wire in most cases)

The buzzing of the MPR ONLY happens if I have turned on the ignition for a while , turn it off and then turn that battery switch off. Voltage at the back of the engine then goes from battery voltage down to the 5-7 volt range. When the voltage is at around 5.5 volts the MRP buzzes . . . does that for a while, then the voltage drifts upwards to 6.5-7.2 volt range and buzzing stops. If I turn the battery switch back on the voltage immediately goes back to battery voltage and the buzzing stops.

Now test the other good engine to see if all the same happens.

PS: In the diagram reference above regarding throttle demand vs coil packs, I see 4 (coils) 41 - 44 as coil packs to the right and 45 as T_D to the left. T_D heads to E-1, Bank C... Morning eyes maybe.

 

[Lou C]

Those were OPD's (other people's drinks)
View attachment 399086
Here is an updated photo from today. The admiral insisted that I stock up for the summer.

Hey Ted you need any helpers lol!
Years ago I was at a NASCAR race with my boss and his son, and one of my best friends we all worked together. All of the sudden the woman next to us stands up and exclaims, OH MY GOD WE RAN OUT OF BEER! It just struck us as hilarous, who cares about who's leading the Pocono 500, dammit we are out of beer!

 

[Lou C]

Quick Update . . .

Alternator wire is Orange (verified) @Fun Times

I found my 9.2 volts . . . Purple wire on the OBD-M fuse socket (2 amp fuse). I'm now updating my diagram to show the purple wire (aka ignition wire in most cases)

The buzzing of the MPR ONLY happens if I have turned on the ignition for a while , turn it off and then turn that battery switch off. Voltage at the back of the engine then goes from battery voltage down to the 5-7 volt range. When the voltage is at around 5.5 volts the MRP buzzes . . . does that for a while, then the voltage drifts upwards to 6.5-7.2 volt range and buzzing stops. If I turn the battery switch back on the voltage immediately goes back to battery voltage and the buzzing stops.

could there be a capacitor somewhere storing current?
I found that out the hard way one day about 45 years ago when I tried to take a timing light apart to "fix" it.

 

[tpenfield]

Just looking at the wiring of the ignition circuit, I am thinking that maybe the nice new alternator is causing the problem.

I'm going to compare things on the port engine, but wondering if I pull the exciter connector off the back of the (stbd) alternator, and the (9.2) voltage goes up to where it should be (12.8 ish) . . . would that indicate a faulty alternator?

 

[alldodge]

I would think the exciter connection should be zero, as in the bridge rectifier should block everything

 

[tpenfield]

Taking a break from electrons today . . . I did some maintenance work on the outdrives.

I noticed that the gear oil had not been changed in a while, and I was starting to get a delayed shift on the port outdrive. After draining down the old gear oil . . . one thing led to another . .

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Here is the guts of the upper housing taken out . . .

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Laid out on the work table - I was going mostly from memory, as I had taken the outdrives apart on my previous boat.

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The cone clutch surfaces definitely had some glazing, so I roughed them up a bit and put it all back together.

Tomorrow is the starboard outdrive's turn.

If I have time, I'll be back on the electrical stuff. . . . but there is Friday. Going away for the weekend. Then traveling much of next week. My days are running out.

 

[alldodge]

That's not Merc lube, is it Mobile 1 maybe ?

 

[tpenfield]

I would think the exciter connection should be zero, as in the bridge rectifier should block everything

Yes, I was thinking either the ignition switch or the alternator . . . something is dragging the voltage down.

 

[tpenfield]

That's not Merc lube, is it Mobile 1 maybe ?

old lube of an unknown type . . .

I have about 8 quarts of the Mercury High Performance lube.