warning horn question

[ddennis]

Hey Guys..I have a 2002 merc 75 on a nitro 700lx DC bass rig.. when I turn on the key shouldn't I get a "self test" tone from the warning module? I ran it low on oil (on purpose) when I changed over to synthetic and the horn went off when the level got low. I have tested the temp warning by grounding out the tan wire at the block and all appears to be working....

 

[Don S]

Re: warning horn question

It should do a self test, (in most cases)
Is this a 2 stroke, 4 stroke, EFI, Carbed, Optimax or?

 

[j_martin]

Re: warning horn question

You should get about 4 beeps when you turn on the key. If it is miswired so that the module gets power on the purple wire with the key off, the only indication you will have will be the lack of diagnostic beeps. It will still function well. I have seen bass boats cross wired that way.

hope it helps
John

 

[ddennis]

Re: warning horn question

Sorry Don..it is a classic 2 stroke carb model.. 3 cyl.

So J_martin...if I have voltage constant on the purple wire, with the key off then it is wired wrong or the wiring was changed at some point?

I really would feel better knowing it was working properly...the way I see it, merc designed it that way for a reason!

 

[Texasmark]

Re: warning horn question

I have an '02 90 with the 3000 console....has the big black button you push to get from shift to throttle only. I also have tested the functionality of the warning system and it works, but I get no beeps when initially turning the switch to ON. Son has a '95 150 and it does as F_R said. I haven't bothered to see why mine doesn't do it also.

Mark

 

[MercGuy]

Re: warning horn question

I have a 1998 115 2 stroke. I have been told by many people that I DO have a warning module, and that I should be getting self test beeps when I turn on the ignition.

I traced all my wiring and I do NOT have a warning module. I bought this engine brand new, and it did not come with a module from the factory.

I own the factory shop manual and in the back of the manual it details the warning system, shows where the warning module is, states that I should hear a test beep when I turn on the key, and how to test it in the event of a failure.

In the front of the manual it has an electrical schematic which clearly shows no warning module, and exactly matches the wiring on my engine.

So, it would appear that Merc shipped some with, and some without warning modules.

After examining the warning circuit it appears to me that the warning module only serves 2 purposes 1) it produces a different kind of beep depending on whether the warning is because of high temp or low oil and 2) it can sound a test beep when the key is turned on.

In my estimation neither of those 2 factors is very important and not having the warning module is one less thing that can break.

Engines that have a rotation sensor on the pump would have to have a warning module to monitor the pulses and sound the horn if they stopped.

Hope that helps...

-Steve

 

[Don S]

Re: warning horn question

Here is from the Merc OEM service manual for your motor.

 

[ddennis]

Re: warning horn question

Under the dash (no small feat for a 6"2 260 lb guy!) there is a tan wire that is disconnected and taped on the tip.. I assume it goes to the ignition sw. somewhere...I suspect that is why the horn wont sound on turning on the key.... Question is...where the heck does it go? the horn does sound when grounding the tan wire at the engine..

 

[MercGuy]

Re: warning horn question

Here is from the Merc OEM service manual for your motor.

Don,

Did you even read my post ??????

Yeah I know about the document you attached, and I can show you about 3 more that say the same thing.

Did you see where I wrote:

"In the front of the manual it has an electrical schematic which clearly shows no warning module, and exactly matches the wiring on my engine."

I think that I provided quite a bit of detail, and logically explained what I found. If you can point out problems with my grammer, or the way that I write please feel free to do so.

If I thought I would do any good I'd scan the schematic from my manual, and take pictures of my engine and let you point out where the mythical warning module that beeps on power on is on my engine.

I'm done on this one, I've lead the horse to water, but I guess the wrong end is facing the pond.

 

[Don S]

Re: warning horn question

Don,

Did you even read my post ??????

Nope, I opened that thread before you posted, put my info together, got a cup of coffee, posted the pics to my site, then posted my reply. Happens to people on forums all the time.

PS: You have a 98 115, the original poster has a 2002 75hp, gee, how could anything possibly be different

I'm done on this one, I've lead the horse to water, but I guess the wrong end is facing the pond.

Get a grip!

 

[MercGuy]

Re: warning horn question

OK Don, my error.

I thought you were replying to me.

I guess I'm just tired of people telling me that all Merc's have warning modules, and that I don't know what I'm talking about.

Please accept my appologies.

-Steve

 

[Texasmark]

Re: warning horn question

Dennis, on your comment about the tan wire under the dash:

I have the '02 90 hp if I didn't already mention it. I didn't look on the remote end, nor under the dash where the instruments are, but I have an additional tan wire on the engine end of the harness (in the engine) that is not used. Gonna bet that maybe this is to hook up a temp gauge if you want one as there is a plugged, threaded hole in the rear of the head's water jacket that could be used for a sensor and tan is for temp.....but just speculation.

My OEM Serv Man is for '94 up so I have to just guess where it stops and what changes Merc may have made later on.

Other thing is, I could never figure out why Merc had things on some engines and none on similar engines, like my engine has no "over rev limiter" and some do......confusing.

HTH

Mark

 

[Don S]

Re: warning horn question

It's BASICALLY the same manual Mark. However it is now revision 4 done in May 2003 that changes a few things.

 

[ddennis]

Re: warning horn question

I will try disconnecting the leads from the starting battery tonight and see if the horn goes off once it is reconnected...

 

[Texasmark]

Re: warning horn question

Thanks Don, anything in particular?

Mark