Alarm Module

[simpleur2]

I have seen some threads on different sites regarding this problem but none have really helped. Sorry for beating this one to death.

I have a 1989 Merc 100 hp outboard and the alarm sounds constantly with the key on or off. I purchased this motor and have never run it yet. I installed a new wiring harness and am pretty confident it is wired correctly. I tested the two blue leads from the low oil sensor, the circuit is open. I tried connecting them with a test lead and it made no difference (I think it is supposed to be open until the oil gets low then the sender completes the connection). The heat sending unit is also open, there is no continuity to ground which tells me it is not sending a hot signal to the alarm module. The tan wire with a blue stripe is going to a temp gauge up at the dash (not a Merc Guage, shouldn't make a difference). The only wire that makes the alarm stop when lifted from the terminal block is the tan wire from the alarm module. If I disconnect that wire the alarm stops. I noticed the tan wire on the alarm module has continuity to its metal case (continuity to ground). Does anyone know if this tan wire should have continuity to ground? My guess is that it should not, all the senders that connect to the module would activate an alarm when grounded and they all share the same terminal. The modules are expensive and I don't want to buy one until I know that's what it is. I have not checked the coil for the right voltage but I doubt that is the problem. I appreciate what ever help someone could give. Does it sound like the problem is the module?

Thanks

 

[j_martin]

Re: Alarm Module

That wire should not ground the alarm circuit unless the switch is on AND there is an alarm condition. Then it should be intermittent (beep, beep, beep)

When 12 volts is initially supplied to it via the purple wire, it should go beeeeep, beep, beep, beep. Then be quiet unless something is wrong.

The alarm module is bad.

sorry
John

 

[simpleur2]

Re: Alarm Module

So it should give an initial 4 beeps then go quiet? The only way to silence the alarm is to disconnect the tan wire from the module. I wish I had a good one to test the tan wire for continuity to it's own metal case prior to purchasing it. No need to be sorry that its bad, I just don't want to buy one and have the same alarm when I'm done.

Thanks

 

[j_martin]

Re: Alarm Module

Unless there's a mechanical abrasion or something shorting the wire to ground, you found the problem.

If you're not sure, get the manual and go through the analysis procedure in the book for the lubealert system.

Basically, here's the run down.
Purple wire gets 12 v when the ignition switch is turned on. Alarm self diagnoses and gives 4 beeps for reassurance.

Inputs to the module are
12 V (Purple)
Ignition pulses (green)
Oil tank cap, normally open, grounds when oil low (light blue)
oil pump motion sensor power to it, and pulses return. (white, blue/white)

Output is tan wire, goes to ground on alarm

Alarm sounds when one or more of the following conditions is met.
low oil, (blue wire grounds)
no ignition pulses while oil pump motion pulses (ignition fails)
ignition pulses and no oil pump motion pulses (pump fails)

Oil alarm is interupted tone, while temp alarm is solid tone.

Solid out of oil alarm is always a fault in the module.

hope it helps
John

 

[gss036]

Re: Alarm Module

Double check your connections at the ignition, I kinda think you have something connected wrong at that end and you are supplying power that keeps the circuit hot. My OEM manual for 1989 on covers the V-6 135-200 hp engines, so can't rely on the wiring schematic.
You mention 2 blue leads from the oil sensor, I don't think that is correct. The rotational sensor for the oil pump is probably a white and a lt blue white. The oil cap is lt blue and black going to ground. The water temp sensor(switch) is blk and blk to ground, when overheated, closes the circuit and sends a signal through the terminal block.Temp guage should be seperate and is tan and goes to the dask guage and is probly seperate from the harness. The only wire going to the alarm (via harness) should be tan/blue.
Maybe that will help or confuse you more, good luck.
John , looks you and were typing at the same time.

 

[simpleur2]

Re: Alarm Module

I think I may have made a wrong statement when I posted this. It is the tan wire with the blue stripe that is causing the ground (not the tan). The harness instructions say this wire is supposed to either go to an idiot light (for temp) or to nothing (says to tape it to the harness if not used). The only wires I have from the module are one black, one purple,one tan, one black and two light blue wires. I tried using the tan/blue wire on the guage, and disconnected with no luck, still alarms. I've tried all kinds of different combinations with the tan and tan/blue wires none helped. I guess I should just buck up and spend the money and see if it does the trick. Lots of people say the tan wire is the temp gauge wire but the motor did not have a lead from the temp sensor that plugged into the female connector on the tan wire that comes from the back of the harness end so I assumed it was the tan/blue wire. Thats the only thing I didn't try. I will make a short lead with an eye on one end and a male connector on the other and connect the tan wire to the gauge. I guess I still need to connect the tan/blue wire to the terminal also (it was connected when I bought the motor and I doubt if the previous owner messed with it. I'll let you guys know if it works.

 

[j_martin]

Re: Alarm Module

The tan/blue wire that goes into the harness (cannon plug) goes up to the control. When it is grounded the alarm should sound.

That wire is used for both overtemp and lube alert warning.

The tan/blue wire from the lube alert should not be gounded unless there is an alarm condition, and then intermittently.

the black wire from a sender on the head is the overtemp switch. It goes to the same tan/blue circuit.

The tan wire is from the temp gauge sender. It goes up to the controls and through to the temp gauge. It is not involved in the alarm.

GET A BOOK AND FOLLOW THE DIAGRAMS/INSTRUCTIONS.

hope it helps
John

 

[simpleur2]

Re: Alarm Module

I have a manual, and the instructions that came with the harness. They are different. I guess I should have bought the $75.00 Merc manual instead of a Seloc

 

[gss036]

Re: Alarm Module

The wiring descriptions which I gave earlier came from Mercury OEM for the 1989 135-200 hp engines. I would assume they would be very similiar.
That info and that from J_Martin is correct.

 

[simpleur2]

Re: Alarm Module

Twas the module. I bought a new one and the old one was bad. Thanks to everyone who tried to help