Optimax Charging Issues......

[nitsuj378]

Good afternoon/evening,

2008 Mercury Optimax Pro XS 250HP
1B550013

Battery - X2 Power (Northstar?)
Group 31M
CCA - 1150
RC - 220

I will try to keep this short with major bullet points I feel are relevant.

November 2020
Running back to weigh in on Chic. (15 miles or so) and got the voltage alarm when hitting the trim switch. Limped back to ramp. 1 week later I changed alternator (cheap one from Amazon) and everything ran fine.

July 2021
Running back to weigh in and hit trim switch and motor completely shut off. Was able to start in back up and idle to ramp. Took it back out following weekend and same thing. Got quoted $600 for OEM alternator from local mechanic but decided to try another $80 one from Amazon thinking I may have gotten a bad one. Installed it and everything ran good no problems.

Fished almost every Thursday night tournament on local lake with no issues until the last one in September. My buddy was in the boat and I launched him. He tried to start the motor and heard multiple fast beeps and clicking from around the dash. I got in the boat and it started fine and we fished as usual. Fished a few times for fun with no issues.

October 10th 2021
Fished a regional tournament. Launched boat fine and took off fine. Ran to first spot no issues. Fished for about 3 hours. Went to run to 2nd spot and noticed the voltage dropped to almost 9V when cranking. Motor cranked but died when I would hit the trim. Sat there for a few minutes and was able to idle back close to the ramp to finish out our fishing day. During the day I tried multiple things to figure out what was going on. I finally heard the clicking/fast beeping (not like a normal alarm beep) when trying to start that my buddy had heard a moth before. When I would hit the trim switch, I could hear a buzzing sound from under the dash. The battery would jump from trolling motor battery but I could only idle.

Today
I read some old forums to check some stuff. Here's what I have done...
Charged battery fully
Load tested battery at Batteries + Bulbs (load tested good according to tech)
Checked 100 amp fuseable link for resistance. Checked good.
Decided to remove panel that has Blue Sea switch panel on it and check connections. On the back on the switch, one of the post was just a tad "wobbly" and the battery cable was the slightest bit "loose".
I then decided to remove the switch completely from the equation. Cleaned and connected battery cables from motor directly to battery. Connections were good and tight. No wing nuts.
Put a meter on the battery and read 12.8V
Hooked up muffs and started motor. Battery read 13.8 after 5 mins.
Check voltage at alternator on red output lead. Read 13.8 with motor running.
Turned off motor and checked voltage at red and purple wire at the alternator. Both read 12.8V with the key on motor off. Check them with key off. 12.8V and 0V respectively.

What am I missing here. I cannot believe that I have yet another bad alternator. I know I went the cheap route but that would be 2 bad ones in a row. What else can I do to troubleshoot this. Any help is appreciated.

Thanks

[Bryanmc57]

Pretty good write up. Battery switches aren't recommended as they tend to cause issues. The experts will be along in a bit. BTW, that's not a serial number.....

[nitsuj378]

Edited. Thanks

[tomloans]

When you hit your trim you are likely having a voltage drop due to a bad ground. I know it sounds too simple but here is my story of a typical issue with these motors...

http://www.bbcboards.net/showthread....light=tomloans

And here is the conclusion excerpt if you don't want to read it all...

"OK guys! Pay close attention to this post before you do anything else if you have a voltage drop due to the trim motor. Problem has been solved because of repeated attempts by Don to get it through my head. I missed a step! A very crucial step. Tonight I started doing searches for a cure for this issue (again). Here is what kept popping up....

-Common ground point on electrical plate (just left of relays): Clean and restack. Remove 3 bolts securing place and ensure the surfaces are clean/grounding well.

and again this from a different post....

-Verify ground wire connections for the trim harness (bundle of ground wires below ECU, at the back of the electrical plate) are clean, and tight- with no paint or liquid tape "leached" in between the connections.

and many other posts from Don.

This comment was popping up everywhere and I hadn't done it. This is where the ground wire for your trim motor is located. Bad ground here and you are done.

Took ground wires off the plate and there was a small film of corrosion at all connections.IT IS HARD TO SEE THE CORROSION - BRUSH ALL CONTACT POINTS ANYWAY. Removed the 3 bolts holding the plate against the block and there was corrosion. Took a brush to all sides of the 3 areas of where the plate connects to the block and to the 3 ground wires and where they connect. As you do this you will see white dust which is the corrosion coming off. Tightened everything back and should be good for another 10 years of this motor.

Perfect voltage now. All is well. Now I can fish in peace. In this case the problem was a bad student of Don's.

Thank you all for your help and a special thank you to both Leon for encouragement and Don for sharing all his experience here. I would have missed the spring bite if it weren't for this forum and his input.

Tom"

[tomloans]

I actually added an external ground wire to the connection point at the 3 wires and connected it directly to the block. This way I don't have to remove the plate again when it happens again and I can simply clean the outer connections. I will try to get a picture and upload it here.

[nitsuj378]

Thank you for your input. I would definitely love to check out this grounding situation. If you have pics or could point me in the direction to where it is located that would be much appreciated thanks.

[castforcash]

Screenshot_20211012-094711_Google.jpg


Screenshot_20211012-094657_Google.jpg

[tomloans]

Hey Justin,

Here is what I did to solve the low voltage thing. It was a combo of Don's recommendation plus one added feature. Corrosion in my opinion is the number one issue when you have electrical problems with any vehicle. This video should be fully loaded available on Youtube by 11:10 AM today Pacific Time.

[nitsuj378]

On my initial check, the 3 wires going to that grounding plate are painted on with no signs of corrosion.

[tomloans]

On my initial check, the 3 wires going to that grounding plate are painted on with no signs of corrosion.

Dustin, you either didn't listen to the video all the way through and/or you didn't read it all above. I made that video just for you! But you missed one of the most important parts of the comments above and the video. Look at post #4 where it states... "IT IS HARD TO SEE THE CORROSION - BRUSH ALL CONTACT POINTS ANYWAY."

You can't see it. Most of the corrosion is behind the plate. If the plate doesn't have good contact with the block you will ring the low voltage alarm all day long. But I get it, I thought exactly the same thing you just stated. LOL Well you can mess around for another 2 months trying to figure this out and still end up doing the steps noted above, or you can do it now and get back to fishing. This voltage drop is not healthy for your motor. If you do end up doing it, don't think/just do! Just brush/scrub hard all the contact points mentioned. Do it word for word according to what Don has stated. You'll thank us later.

[nitsuj378]

I am going to take the plate off and do as you mentioned in the video. I just couldn't dig in tonight due to other family obligations. I just wanted to mention that I did peak at it when I got home just to see if anything stuck out.

Thanks for your help and the video. It's much appreciated. Hopefully I can get to it tomorrow afternoon.

[tomloans]

I just read my post and it came across harsh. Forgive me. Let us know if it solved the problem.

[EuropeanAM]

I just read my post and it came across harsh. Forgive me. Let us know if it solved the problem.

Thanks for noting that... sometimes it's hard to put the correct amount of emphasis on the written word when it didn't "stick" the first time.

[nitsuj378]

Ok. So I removed the plate. I didnt see any noticeable corrosion. I cleaned the ground block on the motor side and the back of the grounding plate.

I havnt gotten to take it out yet. I'm going to try this weekend sometime.

Any other suggestions?

Thanks20211014_161049.jpg

[EuropeanAM]

Do the same with the stacked grounds on the left side of that plate.

[tomloans]

Ok. So I removed the plate. I didnt see any noticeable corrosion. I cleaned the ground block on the motor side and the back of the grounding plate.

I havnt gotten to take it out yet. I'm going to try this weekend sometime.

Any other suggestions?

Thanks20211014_161049.jpg

Please let us know what the end result was.

[nitsuj378]

Checked and cleaned the stacked grounds.

Went out to the lake today and started the motor. Voltage read 11.8. Was reading up to 14.1 at the house. Idled out for a while and voltage never increased. Was kind of scared to run along way and didn't want to get stuck so just ran some short runs by the ramp. Voltage dropped a little after a few.

Why is the voltage not Where it's supposed to be? I know I wouldn't be able to sustain a full tournament t day. I'm stumped and this is getting frustating.

Time for a For Sale sign?

[apdriver]

Making sure you have good grounds is just part of the troubleshooting process. Pretty sure you’ll figure this out. Not time for a fire sale, yet. Don has a great mechanical mind and will help you figure this out. Hang in there!

[tomloans]

Checked and cleaned the stacked grounds.

Went out to the lake today and started the motor. Voltage read 11.8. Was reading up to 14.1 at the house. Idled out for a while and voltage never increased. Was kind of scared to run along way and didn't want to get stuck so just ran some short runs by the ramp. Voltage dropped a little after a few.

Why is the voltage not Where it's supposed to be? I know I wouldn't be able to sustain a full tournament t day. I'm stumped and this is getting frustrating.

Time for a For Sale sign?

Hi Justin,

"I'm stumped and this is getting frustrating" Believe me I know the feeling. I am their now with another issue on my motor.

So this time around, did the low voltage alarm go off when you hit your trim? Was that voltage @ 11.8 when you hit the trim switch or just motoring around? I find that just motoring around at low rpm's, the voltage is low as well. I still think you have a grounding issue and it is something to do with the trim. You stated this in your original write-up...

November 2020
Running back to weigh in on Chic. (15 miles or so) and got the voltage alarm when hitting the trim switch. Limped back to ramp. 1 week later I changed alternator (cheap one from Amazon) and everything ran fine.

Do you recall what the voltage was when this happened? What is the voltage prior to hitting the trim switch? This last time, did you get the motor up to speed and what was the voltage then? My voltage gauge doesn't do much until I start revving the engine.

If it were my motor, I would take the leads off the battery, then take and wire brush all major connections on the motor ( always unbutton the battery because you could easily burn out that 100 AMP fuse). I would wire brush connections at the alternator and there are some other areas I did this with. The repair I noted above solved my problem ( it wasn't a waste of time - this will eventually cause a problem for you ) and it gave me a new sense of the realities of corrosion and what it will do to this engine. Once I go through ( wire brush ) the engine critical connection points, I would wire brush every lead to the battery and terminals as well. Let's see what Don has to say.

[EuropeanAM]

Let's go back to "Square #1" on this. Since you had good voltage, and now you don't, SOMETHING is different.

Let's get DVOM Readings (provide results) for each condition below:

-Voltage at battery BEFORE starting engine (battery charged, left to sit overnight): _________

-Voltage at battery AFTER starting engine (engine IDLING for at least 3 minutes): ________

-If above voltage is lower than 13.4 VDC, Please Continue....

-With engine idling, Voltage at the LARGE RED output terminal on the alternator: ________

-Disconnect small wiring connector at alternator: Voltage on SMALL RED wire: _______

... Voltage on SMALL PURPLE wire: _______

Check voltage from Battery + terminal to engine ground: ________

Check voltage from Battery + terminal to alternator body (metal portion of alternator): ________