'90 Mercury 175 warning module

[ManlyVehicle]

Re: '90 Mercury 175 warning module

JLEHighland, not sure what to tell you about whether it might be your stator or the swithbox because of how the number 4 plug is fouling. I’d like to try grounding my own to see if the alarm goes off, I just disconnected it in my test. However, it sounds like the root problem for yours is probably pretty consistent, and if it is in the stator, the standard stator tests will reveal something before you have to spend the money.

 

[dogsdad]

Re: '90 Mercury 175 warning module

JLE, just a couple more thoughts to share...<br /><br />I have been looking at my Clymer manual, and the curious thing is that it shows only the number 2 coil having anything to do with the lubalert module. Could it be that it has been connected to the wrong coil since it was new?<br /><br />Other thoughts: it may not matter one way or the other, but a fouled plug should look more like a very high resistance to the coil than a short. Also, I was thinking about electrical failures in general, and if a coil's primary is screwed up, it could be either open OR short. To go a step further, a shorted primary could cause both a misfiring plug AND a loss of voltage to the lubalert module...I'm wondering if you already tried swapping another coil into the number 4 position.<br /><br />As I stated in my previous post, I am here to learn, so I ask this: would the ignition system be set up to limit engine power when there is an alarm condition?<br /><br />Someone else mentioned that the lubalert module monitors the rotational sensor relative to a primary spark signal. In looking at my manual, I see that the rotational sensor appears to have a fuseholder in the circuit. An odd thing I have seen happen with fuses is that they can measure good (0 ohms) with an ohmmeter, but still be bad. They seem to develop a certain amount of resistance under load, and the full, intended voltage is not delivered to the intended recipient. I know that's a longshot, but it can happen.<br /><br />In thinking about power limitation during alarms, I guess it wouldn't make sense if it was going to cause plugs to foul, would it?<br /><br />I hope you get this thing figured out, and that you share the solution!<br /><br />Best luck, Dogsdad.

 

[gss036]

Re: '90 Mercury 175 warning module

After reading through this string 3-4 times, I keep thinking of a problem I had with my 9.9 Evenrude, turned out to be a bad coil. Insulation was cracked and opened up when it heated up.<br />I read the troubleshooting info in my old intallation guide and Mercury says to check the coil for correct voltage. Just an idea.

 

[jkering66]

Re: '90 Mercury 175 warning module

I have a 1988 175 Mercury Outboard. I was getting intermittent low oil alarm for the past couple weeks.<br /><br />Last night I bleed off the air out of the oil tank on the engine like my newly purchase manual indicated.<br /><br />Problem Solved.

 

[dogsdad]

Re: '90 Mercury 175 warning module

JLE, has this problem been resolved?

 

[ManlyVehicle]

Re: '90 Mercury 175 warning module

JLEHighland, I just replaced my outer switch box and in the process tested almost everything I could think of (e.g. stator, trigger, #4 coil, and rectifier). All appeared to be fine. So far no beeping, but really time will tell. An additional test I did this time was to ground out #4 spark plug wire, rather than just disconnect it, to more closely simulate your fouled plug; and see if any beeping signal resulted. Grounding out the plug did NOT cause any beeping signal whatsoever. So if your oil system is truly OK, then I’m with you and dogsdad in that the cause could be the stator, the trigger, the switch box, or the lubalert; and that WOODMAN’s tests would be good along with the regular basic tests (those on the stator and trigger are easy with an ohmmeter). Please let us know how you make out. I’ll update you on my beeping. Thanks

 

[BassScratcher]

Re: '90 Mercury 175 warning module

Guys,<br /><br />It's been a year since I submitted my reply to this post (scroll way up). Anyway, I took it to a mechanic and he tracked the problem to the switchbox. Well, this past weekend I got the same symptoms. Started out as one beep from the alarm, then a beep and a little hesitation, then constant alarm and no power. I ordered another switch box today and will be replacing the outer switch box when it arrives. I'll keep you posted. BTW, does anyone know what could keep frying switch boxes? Could it be the trigger? I don't want to go another year and have the same problem.

 

[BassScratcher]

Re: '90 Mercury 175 warning module

Here's my problem post from a year ago:<br /><br />

<br />I just started having a similar problem on my 93 Mariner 200 Magnum EFI. Here's the story:<br /><br />Had the boat on the lake on Sunday. Ran it for about 15 min @ 5K RPM's and it ran fine. Let the boat sit for about 1 hour. Got back in and ran at 30 MPH for about 20 minutes. When I idled down, the oil warning came on (not the temp alarm). The engine oil tank was full and the cap is 1 month old. I checked the water sensor. It was fine. I then started the motor and noticed smoke in the exhaust, so I'm confident I'm getting oil. After this I give it gas and noticed I don't have enough power to get on plane. I immediately shut it down and trolled to the ramp. Yesterday, I put a pre mixed tank on so I could start troubleshooting. First thing I noticed when I started it up in the driveway, was no alarm. I checked the oil pump output anyway. And just as I suspected, I'm getting oil. So today, I took it back to the lake. Backed off the trailer and she ran fine for 15 - 20 minutes. I idled down, shut off the motor and then cranked it back up and let it idle. The oil warning came on again and just like on Sunday, not enough power to get on plane. I could only get it up to 1600 RPM's. In neutral, she sounds great, but under load she bogs down. What could cause a power loss and oil warning alarm at the same time? And how do I go about troubleshooting? Could this be a coil problem on cyl #4? Since I am getting oil to the engine, I think the oil alarm is a result of another problem. Any suggestions are appreciated. I'm stumped.<br />

As I stated in my last post, this happened again last weekend. I did receive the new switch box that I ordered and put it on last night and lake tested. Problem solved! <br /><br />I am a little confused and hope someone can splain to me why this is. Last year when the mechanic tracked the problem to a switch box, he replaced the inner swith box. The inner switch box is connected to 1, 3, and 5. Why was I getting the oil warning if this switch box was bad? Yesterday, I replaced the outer switch box and solved the problem. I understand why I was receiving the alarm on this box because it's connected to 2, 4, and 6, but why did I get the alarm when the inner box was bad?

 

[JLEHighland]

Re: '90 Mercury 175 warning module

DOGSDAD, thanks for bringing your thoughts into the discussion. I have been buried with work for several weeks and have not been able to do any tests or fixes, and will probably be a couple more weeks before I can take the time. But in response to your comments:<br /><br />My Seloc manual also shows the lubalert connected to the #2 coil. II don’t know how significant this is but its an easy test. Your comments regarding the possible effects of a bad primary on #4 coil had occurred to me also and are the reason I included the coil in my original list of suspects. And yet no, I have not swapped out the #4 coil with another, partly because the problem is very intermittent, and partly because the severe power loss symptom makes me believe there is more than one cylinder involved. <br /><br />In an earlier post you raised the possibility that the advance module could be linked to power loss. As for additional black boxes, my motor appears to be equipped only with an idle stabilizer. <br /><br />The apparent inline fuse in the rotational sensor circuit diagram is actually a disconnect plug. I checked and re-checked all the connections related to this circuit and ultimately replaced it for no improvement.<br /><br />All things considered and from ManlyVehicle and BassScratcher’s experience it looks like we may be on the right track with stator, trigger, switchbox. And I hope we’re not changing switchboxes like impellers from now on. (sorry, I couldn’t resist)<br /><br />Thanks for all the input. I’ll let you know how mine goes once I get back to it.<br /><br />JLE

 

[slicerbob]

Re: '90 Mercury 175 warning module

Glad I found this thread, I've been pulling my hair out with similar problems. Got a 94 Black Max 175 hp V6, intermittent oil warning alarm, usually after about 10 minutes running time. Oil cap is OK, and I've changed the sensor today, but still the same problem. I should add that I've already checked the drive teeth to the oil pump and I'm completely convinced that the engine is getting oil. Just today I've noticed that the boats voltmeter is reading off the scale at 18+ volts. I've borrowed a manual that states that I need to check the voltage on the coil lead. Could the excess voltage affect the alarm? and if so where can I try and track it down? I've only had the boat a couple of months (imported from Florida, I'm in the UK) and its getting a bit frustrating, not being able to use it as the UK winter approaches.

 

[ManlyVehicle]

Re: '90 Mercury 175 warning module

Just had a chance yesterday to give it a good run with the new outer switchbox. So far things look good. There was no unwanted beeping; and the engine ran nice and smooth. Hope this keeps up through the rest of the season; I’ll be ready to say the problem is solved then. JLEHighland , DOGSDAD, BassScratcher, and everyone, thanks for all the tips, especially WOODMAN. This has been an intermittent problem for me for at least 5 years. It would be nice if it was actually fixed. <br /><br /> JLEHighland , DOGSDAD, BassScratcher, my lubalert is connected to #4 coil, although a mechanic told me one time to try to connect it to another one (forgot which one) if that was giving me problems. In the diagrams in my manuals, it appears many models use #2 instead of #4. <br /><br />BassScratcher, in the manual diagram, looks like for at least one of the EFI 200 models the EFI module connects into #3 and #5. Maybe that is some how connected to the lubalert?

 

[JLEHighland]

Re: '90 Mercury 175 warning module

I finally got back to work on mine. I replaced the outer switch box, which controls the left bank, 2,4 & 6. I also rebuilt the carbs (had seen evidence of the floats sticking), and had a shop chase down a low water pressure issue that was causing progressively higher temps over the last 5 or 6 years. After doing the normal things again (service pump, thermostats and poppet valve) they then opened the exhaust cover to check for a restriction in the left head (the left ‘stat was only outleting half as much water as the right one) – but everything looked fine there. So they did some air pressure tests to diagnose a leak that turned our to be the gasket on the bottom of the powerhead.<br /><br />So this weekend I took it out and it ran like a top. I could troll for an hour then punch it out of the hole with no hesitation. No beeping either. This is a huge improvement and I hope it lasts.<br /><br />I talked to the shop mechanic about the ignition problems and my replacement of the switch box. He indicated that they usually fail due to another problem higher up in the circuit and with time will likely go bad again until the root problem is solved. And I also ran across this advice from http://www.outboardparts.com/troubleshooting/printguide.htm : an engine that repeatedly blows power packs (switch boxes) should have the coils replaced on the misfiring cylinders. <br /><br />But, like ManlyVehicle, BassScratcher and Woodman, I hope this turns out to be a lasting fix. Thanks for your input! And thanks Dogsdad for your interest. Hope this helps.<br /><br />JLE

 

[JLEHighland]

Re: '90 Mercury 175 warning module

 

[dogsdad]

Re: '90 Mercury 175 warning module

Hey there JLE.<br /><br />Funny that I am here this moment, you posted only a few moments ago. Good to hear that things are looking up with your motor.<br /><br />I have had some misadventures with my own boat with a Merc 135 on it...both threads are here and active still. It turns out that I have a bad switchbox myself, I just found it today and plan to replace it tomorrow. Then I will test on the water. <br /><br />I've made a lot of mistakes already, but learned some from them and from the board here. I guess it just never ends!<br /><br />Good luck to you.<br /><br />-dd-

 

[JLEHighland]

Re: '90 Mercury 175 warning module

Dogsdad, good luck… I hope you found the problem… let us know.

 

[ManlyVehicle]

Re: '90 Mercury 175 warning module

JLEHighland, great to hear that your V6 performance is back. I’ve been out a few more times since the outer switch box was replaced. There is still no unwelcome beeping, and better yet my performance is crisper. This was the first time I’ve replaced a switchbox, so I don’t expect a reoccurrence for a while. However, its great to know that if there is then the coils or stator may be the root cause needing replacement as indicated in that website you mention.<br /><br />Thanks to all of you thoughtful boaters (e.g. JLEHighland, BassScratcher , and especially WOODMAN) for posting useful information that has led to more happy boating for me, and my family!

 

[NICK JONES]

Re: '90 Mercury 175 warning module

JLE Highland and Manlyvehicle, great that you solved these problems. For future reference you might also like a bit of info on bad stators as like switchboxes these also seem to go wrong all the time.(Triggers hardly ever go wrong). As well as oil alarm trouble I also had a bad stator. The boat was very slow out of the hole and also cut out quite often at idle. It was also very slow to start from cold, needing around 30 seconds cranking. With the motor running at idle you could withdraw any plug lead about 1/2" away from the spark plug top (not quite far enough for the shroud to reveal the top of the spark plug) but you could clearly hear the spark jump the gap. On a car or motorcycle this would be regarded as a good spark. The ohm readings of the stator were however out of tolerance and against the advice of the main dealer (said don't read too much into the ohm figures) I replaced the stator. The performance and cold starting has been completely transformed and interestingly when you pull a lead at idle the spark jumps nearly 2" to the cyl head. (make sure you use an insulated plug cap puller). <br />Some say that you shouldn't pull leads on these as if the spark has nowhere to go it could damage a switchbox, so just in case there is some truth in this make sure you let the spark find an earth ! (Also note that the bad stator had previously passed the Merc spark cranking test at the main dealer and also dyno test!) <br />Going back to oil alarms, I think the system is basically very good and it's worth keeping running. If you disconnect it and pre-mix you may not notice an ignition problem that you have developing. Also to anyone with oil alarm problems remember that if the oil pump gear fails you will still get plenty of blue smoke at idle, as there is enough pressure in the oil header tank to force some oil past a non rotating pump ! Enough oil for idle but not enough for higher revs ! Don't ever dismiss an oil alarm as a false alarm ! Somewhere in this forum I've written quite a bit about fault finding oil alarms, a search on my Member number will find it all.

 

[JLEHighland]

Re: '90 Mercury 175 warning module

Here I am 2 years later thinking about switchboxes again! Replaced the outer s-box October ’03 and engine has run great ever since… until yesterday. Similar intermittent rough running and loss of power, unable to get boat to plane. This time, however, I’m not getting the oil alarm, but instead the temp gauge reading drops to ice cold during these episodes. This tells me the other switchbox is failing, now affecting cylinders 1, 3 & 5. With no ignition on any cylinder, the portside head goes cold which is where the gauge sender is. I have about 400 hours on the outer s-box and about 1500 hours on the original inner s-box.<br /><br />My inclination is to replace the inner s-box without further thought or testing. Either the original switchboxes were prone to failure all by themselves or (as noted above) they have failed due to another problem in the circuit. I suppose there is merit in chasing the problem to its source, but they are easy to change and are now cheaper than a tank of gas.

 

[KCLOST]

Re: '90 Mercury 175 warning module

When you replace the original "mercury" switchboxes, both need to be replaced at the same time... That inner box can easily be your problem now... It is known that even though one switchbox is good, if you replace the other one only, it may lead to a failure on the good one rather quickly...<br /><br />This does not apply to CDI/Rapair swithboxes however...

 

[chris77777]

Re: '90 Mercury 175 warning module

Originally posted by JLEHighland:<br /> 1990 Mercury 175 OB, Model No. 1175422GD / SN 0C139827 (estimate 1100 hours, all mine)<br /><br />Beeping from the oil mix warning module has been an intermittent problem for several years. This is the beep, beep beep signal, not the solid horn sound that would be triggered by the heat sensor on the powerhead. Here is some history:<br /><br />· Oil injection pump was replaced by mechanic – did not help.<br />· New batteries – no help.<br />· Cleaned the strainer in the remote oil tank to improve oil flow to the on-board tank – this helped but did not completely solve the problem.<br />· Cap on the on-board tank is new, tight and the float switch is working properly; oil level in the tank is good.<br />· In the past, the beeping would come and go during some outings; I would rev the engine in neutral or stop and re-start the engine to make it stop. On a recent trip, nothing would make it stop. All systems checked out OK, so I added oil to the fuel tank to create a 75:1 mixture as insurance, then disconnected the power lead to the warning module to stop the noise and continued operating for the day.<br />· The bearing assembly for the drive gear to the oil mix pump was recalled and redesigned at some point; this is the part that houses the magnet that is picked up by the rotational sensor; replacing this part did not solve the problem.<br /><br />Adding the extra oil to the fuel ended up fouling the plugs and I discovered that by merely cleaning the #4 plug I could get the beeping to stop! At least until the plug re-fouled. It turns out the primary voltage to the #4 coil also provides the warning module with rotational data. I suppose the fouled plug provides a ground to the ignition circuit causing a change in the input voltage to the warning module, which then sets it off.<br /><br />I’m pretty sure that replacing the plugs will help a lot, but I have to believe this is not the root problem. What is the most likely problem and how can I test for it? A weak coil? Could I move the module wire to another coil as a test? And what caused the beeping prior to the plug fouling? Any other thoughts? I’m OK with a VOA meter, but that’s about it.<br /><br />Thanks a bunch in advance,<br /><br />Jim