Promax 300 alarm beep after overheating

**86 apache 22** · 07-11-2006, 03:46 PM

Relatively a new member and thankfully I haven't been in need of tech help until now. Well the other day I picked up seaweed in the low water p/u of my 1998 300 pm. Alarm sounded(continuous Beeeeeeeeeeep). I ran it for about a minute to get away from traffic and shut her down. I pulled the debris from the p/u , started the motor and it cooled within mins. Everything seemed to be normal except now it has a Beeep....Beeep....Beeep...Beeep whether the motor is running or just ignition switched on. I shut it down again, checked the oil res. and the remote tank, both full and the motor smoked as normal and temp stayed at 120 deg. so I ran her back to the marina. 2 days later it still beeps. Can someone out there give me some clue, I have nothing more to look at. Thanks in advance. Alex

**HighVelocity** · 07-12-2006, 02:32 PM

Alex,

Just for giggles, take the fuel filter on the motor, off and dump it. Then reinstall it. Let us know if the beep goes away. It doesn't cost anything and you can rule out something. Also, look carefully at the whole motor, make sure you didn't knock of a sensor lead somewhere.

My beep pattern was the same beep,,beep,,beep short pause then again beep,,beep,,beep. It was the filter. The computer never took power away from the motor. I don't think you hurt the motor, I think it's a coincedence that it happened at the same time.

HV

**86 apache 22** · 07-12-2006, 06:37 PM

Thanks for the input. I pulled the wire off the bottom of filter when this all went down and it still beeped. Then while I've been searching for anwsers someone else had mentioned that it would not have mattered since I never grounded and w/o grounding it, it should beep.
Thanks, I'll let you know what happens.

**03bignasty** · 07-12-2006, 06:44 PM

Sounds like a bad map sensor to me. I had that same beeping even when you turned ignition and didn't start it. I'd check with some of the motor guru's though but that's the problem I had.

**86 apache 22** · 07-12-2006, 06:54 PM

Thanks For The Tip. Noone Else Had Mentioned That. Is There A Test For That? It'll Probably Be In My Shop Man.

**03bignasty** · 07-12-2006, 10:08 PM

I have a buddy with a 300 pro max. It takes 2 seconds to remove the maf sensor. I put mine on his and his began to beep. That identified the problem for me. If you know anybody with a 300 or a 280 do that. They are interchangeable with the 280 maf sensor.

**86 apache 22** · 07-12-2006, 10:54 PM

thank you bignasty

**Dean Dorsey** · 07-13-2006, 12:11 AM

Alex, 4 beeps followed by a pause is usually a low oil sensor. If you trimmed the motor all the way out to clear debris from the intake, sometimes the pressure is lost to the remote tank. Check again the res. tank if it is low, even 2 inches from the top the warning will go off. If it is the case fill the small tank almost to the top, turn the key and see if the beeps stop. If it stops then that is the problem, but you may have torn a hose when trimming all the way out, or have a loose cap on remote tank. If this system gets air into it it will not pump oil from the large remote tank to the small reserve one. If the problem occurs continually you will have to find the leak. If this is the situation and the leak can't be located let me know and I will give you some helpful hints to locate it. Also check the oil sensor bullet connectors to make sure you have a good connection, and no short exists. Dean

**HighVelocity** · 07-13-2006, 07:28 AM

I think if you don't find anything by doing the simple stuff, the "Tool" will save you time and frustration. Do you have a local guy who won't rape ya? If not, you can get the tool from someone on this board. At some point I ask myself what is my time worth and how much time am I putting into this.

HV

**Powerplay25** · 07-14-2006, 03:39 PM

Yo Alex!

I have the answer! You can buy my Powerplay!

http://www.offshoreonly.com/esvon/page-11225.html

**Powerplay25** · 07-14-2006, 05:05 PM

Just kidding pal. Hope you get it straightened out so we can go boating Sunday.

**86 apache 22** · 07-14-2006, 09:27 PM

A few brewskies later brings out your guilt ?

Well, it wasn't the fuel/water sep.
I was just reading in the shop man that a failed map sensor will make the engine run rough at idle so a simple test is to unplug it and hopefully there is no change.
I fired it up today and it's definitely getting oil by the way it smokes. Also, from the way I'm understanding the manual if it were the oil injection, the alarm would sound during operation but no where does it say that it will beep while not running except as an initial alarm when the key is turned to on just to know that the system is functioning. I guess I'll go out there after work or wait until sunday to unplug the map sensor. I'm also going to take a meter w/ me and check for sensor continuity. We'll see but I doubt I'll be out there Sunday.

**03bignasty** · 07-14-2006, 09:52 PM

My money says its the map sensor.

**86 apache 22** · 07-15-2006, 10:50 AM

This weekend is going to be too much like work! I just went to the boat to unplug the map sensor while running at idle and now it won't even start(before I could even unplug it)...like it's not getting spark or fuel. Cranking fine and has fuel but no start. Then........boat lost all juice from the batteries, everything and after sitting the power came back like the trim, lights ... but you turn the ignition switch and nada, like it has no juice at all....nothing nothing. What to do now ?

**Dean Dorsey** · 07-15-2006, 07:56 PM

I am still going to go along the simple route,as every time I thought I had a complex problem a little time to sit and stare at the motor with a beer cured my problem. I am going to guess the new problem has something to do with what you have done in the process of trying to cure the other problem. This sounds definately like a short or bad connection. If you unhooked the Ign. and or fuel ECM harnesses do it again when reconnecting make sure you hear the click assuring that they are all the way in. same holds true with anything else electrical you disconnected when trying to cure the beep thing. Other things would be to make sure under the electrical cover the fused one, that you don't have a loose main power or ground cable, or anything grounding on something that shouldn't be. I may be way off base at this point but very little goes major wrong with these motors in my experience and simple has solved almost all of my woes with this motor. Very different from my 260 EFI days.
Good Luck, Dean