Troubleshooting Buzzer in 1995 70hp Johnson

[ChrisMA]

My engine is running great, but the buzzer is non-functional. When I ground out the temp switch wires (either the tan/blue or the white/black) on either the engine side or control side and turn the key to run the buzzer does not buzz. I took the cover off of the controls and wired the buzzer directly (purple positive, cream/blue negative) and the buzzer works perfectly. The factory manual is a bit wrong in the regard that to test the warning horn you should ground the single wire that comes out of the temp switch when in fact there are two wires. I know the buzzer doesn't work in practice since my engine overheated and the buzzer did not sound.

I look at the control wires under the engine cowl and I cannot find the cream/blue wire to trace it back to troubleshoot. What color is the buzzer wires back at the engine?

I have also noticed that the two conductor black wire coming out of the oil tank is not connected to anything either. It looks like a ground wire plus a signal wire. It seems that someone may have completely disconnected the alarm system in the past? The factory manual seems to be useless when it comes to control and oil tank troubleshooting.

Chris

 

[ChrisMA]

Re: Troubleshooting Buzzer in 1995 70hp Johnson

So I did a little more reading, it seems that the purple wire at the buzzer should be 12v when the ignition is on and the tan/blue wire is connected to all the sensors (Temp, VRO, engine computer) which go to ground to activate the buzzer? When I had the ignition on and grounded out the tan/blue wire the buzzer should have buzzed? I either do not have 12v at the purple wire at the buzzer, or I do not have continuity in the tan/blue wire from the buzzer to the engine? After plugging and unplugging a few cables the buzzer chirps when I turn the key to run which it did not do before.

Chris

 

[Fed]

Re: Troubleshooting Buzzer in 1995 70hp Johnson

Plugging & unplugging probably cleaned up a bad connection.
Now that you know how it works check the big red plug for dirty contacts.

 

[ChrisMA]

Re: Troubleshooting Buzzer in 1995 70hp Johnson

Plugging & unplugging probably cleaned up a bad connection.
No that you know how it works check the big red plug for dirty contacts.

It is a 1995 motor, but I don't have a big red plug, just 3 smaller black ones, two square ones and one triangle shaped one.

Chris

 

[Fed]

Re: Troubleshooting Buzzer in 1995 70hp Johnson

When I had the ignition on and grounded out the tan/blue wire the buzzer should have buzzed? I either do not have 12v at the purple wire at the buzzer, or I do not have continuity in the tan/blue wire from the buzzer to the engine?

Either way you have got this part 100% correct so all you have to do now is find the fault that isn't there anymore. Good luck.

 

[ChrisMA]

Re: Troubleshooting Buzzer in 1995 70hp Johnson

Either way you have got this part 100% correct so all you have to do now is find the fault that isn't there anymore. Good luck.

Thanks, I will see if I can get the buzzer to sound at the engine harness and work back from there then. Does the purple supply for the buzzer come all the way from the engine? I think it does.

Chris

 

[Fed]

Re: Troubleshooting Buzzer in 1995 70hp Johnson

I think the purple supply comes from the 'A' terminal on the keyswitch, it is powered from the 'B' terminal whenever the key is in the 'ON' or 'START position.
So,
key off = no power to alarm.
key on = power to alarm buzzer, same for 'start' position.

After that, grounding the other side of the buzzer should make it work.
If the fault was still there you would find it in 5 minutes with a voltmeter.

 

[clanton]

Re: Troubleshooting Buzzer in 1995 70hp Johnson

The white black wire will not sound alarm, only for Quick Start and S.L.O.W. the alarm only works for over heat, low oil, no oil. A 95 engine with those connectors instead of large red connector probley should have a tach with the 4 red lights, and the tach has the logic to work the horn. Old style system had a horn with the logic made on the back of the horn. You need to know which system you have.

Are you premixing the oil fuel??????????

 

[ChrisMA]

Re: Troubleshooting Buzzer in 1995 70hp Johnson

The white black wire will not sound alarm, only for Quick Start and S.L.O.W. the alarm only works for over heat, low oil, no oil. A 95 engine with those connectors instead of large red connector probley should have a tach with the 4 red lights, and the tach has the logic to work the horn. Old style system had a horn with the logic made on the back of the horn. You need to know which system you have.

Are you premixing the oil fuel??????????

My date code is EO which puts the engine at 1995 which I thought was the last year of the old style controls. I do have a small 4" x 4" x1.5" control box in my console. How do I tell the new style from the old style controls?

I'll troubleshoot the wiring further tonight and see what I come up with.

I did premix the fuel for the first 10 hours, but since I have seen the oil level in the tank drop considerably, I have stopped premixing.

Thanks for all the help.

 

[ChrisMA]

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

I went out this morning and traced two brown wires at the top of the engine, I grounded one out and the buzzer immediately signaled. I guess I put the harness back together wrong. I have another question though, as you can see in the left side of the photo the tan/blue and white/black wire come out of the temperature probe and I had these both plugged into the white/black and tan wire on the right side of the photo for which these two wires appear to go to the engine computer. In the middle of the picture were two tan wires that were not connected to anything.

Background information is the engine drastically overheated a few weeks ago and the buzzer did not sound (head temp 300 degrees, yes I checked the compression afterward and it was fine) The overtemp was due to a part missing in the thermostat/vernatherm

Three questions:

1. Should I plug the temp probe into the tan wire in the middle?
2. Where should that tan wire on the right be plugged into, or should I just tie it off?
3. Where does the oil tank sender wire plug into?

Thanks,.

Chris

 

[clanton]

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

I don`t have that wiring diagram with me, and busy tomorrow. Be late tommorow or Thrusday before I get back.

 

[clanton]

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

Your engine has old style harness.
The Oil sender should connect to two loose wires on port side of engine, 1 black wire male connector, 1 tan wire female connector. VRO should be connected to connector with 4 wires, black, purple, tan, gray.

Engine harness should connect to control harness, with large red connector, port side of engine.

The top tan wire in photo. Does it have yellow marking, or just dirt?

 

[ChrisMA]

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

Your engine has old style harness.
The Oil sender should connect to two loose wires on port side of engine, 1 black wire male connector, 1 tan wire female connector. VRO should be connected to connector with 4 wires, black, purple, tan, gray.

Engine harness should connect to control harness, with large red connector, port side of engine.

The top tan wire in photo. Does it have yellow marking, or just dirt?

Top tan wire just has dirt on it. I figured it out, the wire on the left is the "source" for the horn from the engine computer, it simply plugs into the other tan wire on the left. I am not sure if I have newer controls or my 1995 motor is somewhat of a transitional design, or someone put new engine connectors on the motor, but I do not have a large red plug. I have 3 small black connectors, one triangle shape, and two square ones.

You know, I just looked in my shop manual and I see the big red plug, I think I am running newer controls with this older motor. There are a bunch butt connectors as well near the 3 black plugs. I definitely do not have a large red connector, I'll post a photo later.

Chris

 

[clanton]

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

If you are going to run the VRO. Connect the wires to the VRO pump and oil tank. Trace the tan wire farward to the control. Verify this is the same tan wire going to temp sensor, VRO pump, and oil tank. This will be the sensor wire, Then you need purple from switch, hot with key on. Cheap and simple connect to new style horn. This will not have self test and will only sound countious when there is a problem. Over heat will set S.L.O.W.
If you want the orignal set up, you will have to verify the oil tank sensor is old style, and buy the old style horn with the logic on the back side of horn. This will give you self test, alarm for over heat, no oil and low oil. Over heat will set S.L.O.W.

 

[ChrisMA]

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

If you are going to run the VRO. Connect the wires to the VRO pump and oil tank. Trace the tan wire farward to the control. Verify this is the same tan wire going to temp sensor, VRO pump, and oil tank. This will be the sensor wire, Then you need purple from switch, hot with key on. Cheap and simple connect to new style horn. This will not have self test and will only sound countious when there is a problem. Over heat will set S.L.O.W.
If you want the orignal set up, you will have to verify the oil tank sensor is old style, and buy the old style horn with the logic on the back side of horn. This will give you self test, alarm for over heat, no oil and low oil. Over heat will set S.L.O.W.

Interesting, does the old style horn have several different inputs for the different alarms? I was struggling to figure out how a simple horn could send different tones with just a power lead. I will leave the oil tank alarm disconnected since I can check it by sight anyway. I am fairly certain I have newer controls with the older engine now. This means that all alarms will just be a single tone I assume? I guess I will be protected from overheat and no oil in the vro is that correct? I guess I shoudl disconnect the oil line while running on premix and make sure the alarm sounds.

Chris

 

[clanton]

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

Re: Troubleshooting Buzzer in 1995 70hp Johnson - Partial Success

What I call the old style horn has logic on the horn, when sensor sets, the logic decides which sensor and beeps the horn. System check has wires from each sensor to tach. The realy old style only had overheat. I think old style engine harness, waste of time, money hooking up System check tach. The new style harness also has wires for regular tach. 3 different alarm systems. I may do a sticky with color wiring diagrams one day. Hook everything up, ground the tan wire from for overheat sensor, work the float in the oil tank. block the oil line for about 10 minutes. run engine on 50/1 in tank,