Low voltage alarm going off when engine is running????

[TIM MANN]

I have a ranger z 20 with a 225 pro xs. I have the small rectangular smart craft gauge. When I am running and begin to use the trim and or use the hydraulic jack plate I am getting a low voltage alarm!!! It sounds off but stops as soon as i let of the trim It doesn't go off when i trim the motor when the engine is off with the ignition on. Why is this? Is there a way to program the alarm not to go off? When I trim the motor in the driveway, the voltage reads 11.5 while trimming with the engine off. I Checked for tightness at the battery post. I also checked for corrosion and I am ok. Lock nuts are being used instead of wingnuts. Any help would be appreciated.

[Shef]

What battery are you using and how old is it? Are the engine cables installed first then acc.cables. Usually a sign of a waek battery.

[EuropeanAM]

Suggested steps:

-Charge battery fully and LOAD TEST to confirm it meets (or preferably EXCEEDS) the minimum Specification of: 800 CCA or 1000 MCA

-Confirm ENGINE CABLES are installed on battery posts FIRST, remaining lugs stacked largest to smallest, then finish off with Stainless Locknut (wrench tight).

-Confirm ENGINE END of battery cables are clean and tight (especially the GROUND cable, located down below the starter).

-Verify battery voltage with engine running. After approximately 5 minutes, you should be seeing 13.1-13.9 VDC (approximately).

[TIM MANN]

The battery is 800cca. All conections are good and it is putting out 12.4 volts per the smart craft. I started the motor and it seems to go up to 13 volts. I began to trim and raise the jack plate i DID NOT get an alarm at idle. I then gave it gas and maintained 2000 rpms. The volts went up to 14.7. I then hit the trim and jack plate and the Alarm went off giving me a voltage alarm. So apparentley it only sounds off at highter RPMS. Could the fusible link be blown. If it was blown, would it still raise volts on the smart craft when giving it gas? Here is the other issue....The boat is new to me and it has a battery switch on it for emergency "jumping" off a trolling motor battery. Stupid me didnt realize why there was a red wire just hanging and i touched it to the negitive by accident on the crank battery which arched the battery for a split second. This all happened before the first time I water tested it. Could I have blown that 100amp lead? If it is blown then why is it still raising my volts at 2000 RPMS.

[EuropeanAM]

Although short circuiting the circuit CAN cause the 100 amp fusable link to blow- it's not possible for the alternator to charge with the link BLOWN (at all). This doesn't necessarily mean that it's IMPOSSIBLE to "partially" burn out the link (it's just not likely).

You stated your battery was 800 CCA. Precisely what did you base this statement on?

[TIM MANN]

Ok, i performed a battery of test...No pun intended! I took the battery out and I assume the battery is at least 3 years old since the boat is a 2007 model. I took it to Advanced auto an had them test the battery. The print out said that the voltage was 12.86, measured 922 cca....then he did a marine test and is was 12.85 volts and measures 1197mca.....He said the battery had no dead cells and was perfectely fine. I then wire brushed the terninals and put the batery back with locking nuts. I then tested the voltage off the starter coil and the ground wire conected to the starter. It came out to 12.89 volts. I then tested the voltage on both sides of the fusible link and both sides tested 12.78 volts. I started the motor and let it idle....after a few minutes voltage raised to 13.70 volts, with no alarm. I could use the jack and trim with no alarm. I then gave it some gas and raised the RPMS to 2000. Again no alarms sounded off and I was able to still use the trim and jack without it going off. Volts at 2000 RPMS was 14.78..... I then gave it a little more gas and once RPMS went just over 2000 rpms, an alarm sounded off and showed an engine icon and the voltage icon. HOWEVER, this alrm was Beep Beep Beep Beep rather than a constant tone. Volts was 14.8... NOt so sure it is the fusible link now....by the way, i put the volt meter on the lead that connects to the battery and the volts do raise as you increase thr rpms...so that tells me that it is charging the battery... could the smart craft be sounding a too much voltage alarm? at higher rpms?


Modified by TIM MANN at 3:09 PM 1/2/2011

[EuropeanAM]

Tim:

You need to have your engine placed on the Computer Diagnostic System, and have a PRINTOUT of the Freeze Frame (Fault) History done.

I'd be more than happy to review this printout for you.

We've been working off the premise that you had a low voltage alarm.... when indeed, it may be something completely different (or may be two separate problems).

Some of the possibilities (there are many more):

-Water in Fuel
-Low Oil Level
-Shift Position Switch Malfunction (or attempting to rev engine in neutral)

[TIM MANN]

Took it out yesterday and it is defiinentely a Low voltage alarm. The battery drops to 10.8 when i hit the trim for more that 4 seconds which activates the alarm. As soon as I let of the trim it jumpes back to 12.5 and then eventually up to 13.5. As the day went on the alarm seemed to go off even more frequent. SOOOO... i then put a Cabelas 27 AGM battery in. It worked a whole lot better. At 3000 RPMS i was getting 14.2 volts. at WOT i was getting 13.1 volts. I het the trim and it dropped to 11.1 volts and activated the alarm. But it was way better. It seems to me that the motor is sending volts to the battery hence the 13.1 and 14.2 volt reading. Gonna charge the cabelas battery up to full charge and see what happens. Next will be a trip to the mercury shop. Very frustrating...

[EuropeanAM]

Tim:

Check the NEGATIVE battery cable, where it attaches to the ENGINE BLOCK (down below the starter). Even if the bolt is tight- the cable could be loose.

[TIM MANN]

I will check....thanks

[cmpky]

I had the same thing happen last year on my 03' 200 EFI. I did all the checks and it turned out to be the fusable link that is attached to the positive side of the alternator. I think it cost about $60 at my local shop. Replaced it myself and took about 15 Min. Good Luck

[TIM MANN]

Don, I finally took my rig into the Merc dealer. The mechanic called me an hour later and told me that I had a hole in the block/ water jacket, that was causing water to spill on my alternater. This was causing my voltage to go crazy. New powerhead on the way. He did tell me that it was a manufactured power head from mercury marine. Apparently it's a new block and pistons but some parts in the power head have been refurbished. But the powerhead is built by mercury marine. I would have never thought this was going on!!!

[EuropeanAM]

Tim:

Glad to hear they found the problem for you. Not a very common problem.

This is one of the reasons we deal with Mercury Marine.... in my opinion, their customer service is second to none

The remanufactured powerhead you'll receive is built to the same (perhaps better) standards, and should serve you VERY well.

[TIM MANN]

One more question Don. What parts will be "used" in the block. I am assuming the block, bearings, and pistons would have to be new parts. And why do u think that the powerhead will perhaps be better than a factory unit. I also want to personally thank you for taking your time to stop and answer all of our questions. I am sure your shop is second to none. Thank you, Tim

[EuropeanAM]

Which parts are re-used depends COMPLETELY on the condition of parts when the powerhead was inspected (after disassembly). ALL parts are required to be within factory NEW tolerances when reassembled.

This would include bearings, crankshaft journals, rods, pistons, etc. Most commonly, new pistons, rings, bearings, seals and gaskets are utilized. In some cases.... it's ALL new.

The tolerances used during Remanufacturing are actually "stricter" than factory assembled powerheads (and a strict system of HAND-DONE checks are utilized).

[TIM MANN]

Thank you, I was somewhat worried that they were going to give me a used worn engine.

[rocketmanjp]

I know you had other problems and glad you got them identified. One thing Don failed to mention to you is that these motors have an alarm if you rev it higher than 1500 RPM's in neutral. That is why you were getting the engine alarm in addition to the low voltage alarm when testing on the hose in neutral reving up to 2000 RPM's.

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by rocketmanjp &raquo;</td></tr><tr><td class="quote">I know you had other problems and glad you got them identified. One thing Don failed to mention to you is that these motors have an alarm if you rev it higher than 1500 RPM's in neutral. That is why you were getting the engine alarm in addition to the low voltage alarm when testing on the hose in neutral reving up to 2000 RPM's.</td></tr></table>

Correct on the rev limiting feature in neutral (although the precise RPM figure does vary).

However.... his results were occuring IN GEAR.... and a neutral overspeed fault "shouldn't" be affecting battery voltage.

Of course, a leak in the block that's flooding water into/onto the alternator was very likely a contributor. Since water pressure increases with RPM's (as does water volume)... the faster he ran the engine, the more water was flooding. Strange things occur inside an alternator when it's flooded with water... and these engines DEFINITELY require adequate voltage.

[TIM MANN]

Well folks, the engine is repaired and i pick up the boat tomorrow. Gonna put a few hours on it. (proper break in) The powerhead is a remanufactured block. I have read some mixed reviews online about the remanufature process such as merc using oversized pistons in some cylinders and leaving standard size pistons in other cylinders. Is this a remaufacturing process or a rebuild? Some say Merc would not do that and that all pistons will be the same size. I also read that all of the internal parts will be new other that the block. Don, what is true and what is fiction?? IS this powerhead going to be as good as a new powerhead? Will it last?

[EuropeanAM]

It would indeed be REMANUFACTURED. This is done in Mercury's Remanufacturing plant.

As stated earlier, ALL internal comonents must meet stringent tolerances after inspection. Exactly which components are "new" depends on what the tolerances SHOWED when checked (anything outside of tolerance must be replaced).

Mercury backs their remanufactured powerheads with the exact same warranty as a "new replacement powerhead".

It should be as good as (or even better than) new.... I've used many of their Reman Powerheads and have had VERY good results.