1988 Johnson 150 ignition alarm question

[winfieldh]

Hi,

I'm wondering if this is normal behavior....

If I turn key switch one click right to on, I get normal chirp. If I then turn it back to off, and then back to on (without ever starting motor), I get continuous beep, so turn back off. If I let sit for 30 secs or turn battery off and back on then I can turn key switch back to on and get single chirp.

Is there a way to test this circuit? I know this is oil/temp alarm. If I disconnect the temp probes and oil circuit, should the alarm still sound? I seem to remember reading about a way to test this using tan wire at electric panel on std side of motor, but can't find post.

Thanks,
Winfield

 

[Joe Reeves]

Re: 1988 Johnson 150 ignition alarm question

The test beep will sound even if all of the sensors were disconnected.

Tan wire at horn must be connected to terminal closest to the built in black ground wire. If otherwisw, weird things will happen.

With horn beeping constantly, remove tan wire from horn. If horn continues to beep, replace the horn. If horn stops beeping, one of the sensors may be faulty.... start disconnecting the sensors (VRO, overheat sensors, fuel restriction vacuum switch, oil tank) until beeping stops. That should tell you which sensor is acting up.

(Testing Warning Horn)
(J. Reeves)

On VRO equipped engines where the VRO automatic fuel/oil setup is still being used, make sure that all components are connected as required. This would include the VRO pump wiring harness itself, the oil tank wiring, the overheat sensor(s), and if so equipped.... the vacuum switch that is standard to many V6 & V8 engines.

If the VRO automatic setup has been eliminated and has been disconnected properly, and the fuel and oil is being premixed, make sure that the overheat sensors are still connected, and the vacuum switch if the engine is so equipped.

On engines prior to 1984 which have no VRO setup, ignore the instructions pertaining to the VRO components, etc above.

Turn the key to the ON position (Engine Not Running). Find the TAN wire at the cylinder head(s), then ground out the portion of that wire that is part of the engine wiring harness. If that Tan wire connector has the knife type connector where as it is exposed simply by sliding the rubber insulator back, it does not need to be disconnected.

Grounding that TAN wire should cause the horn to sound. If it does not, find out why as that's the only warning you'll receive should the engine overheat or have some portion of the VRO system fail, or have the engine encounter a fuel restriction if it is equipped with a vacuum switch.

(VRO Horn Warnings)
(J. Reeves)

NOTE: I retired around 1991/92. Possibly some of the later V4 engines and others may also incorporate a fuel vacuum switch that would enable a fuel restriction warning to sound as mentioned below, an unknown factor to myself.

1 - A steady constant beep = Overheating - The V/6 engines, possibly some others, have a fuel restriction warning which is also a steady constant beep.

2 - A beep every 20 or 40 seconds = oil level has dropped to 1/4 tank. (Late model engine = Every 40 seconds)

3 - A beep every other second = VRO failure, air leak in oil line, oil restriction, (anything that would result in a lack of oil being supplied to the engine).

NOTE - If the warning horn is the black plastic (overpriced) three wire type horn, the warning horn should beep once when the ignition key is turned to the ON position. If it does not, it is either faulty or someone has disconnected it (a stupid move!). At any rate, if it does not beep which indicates that the horn is non functional, find out why and do not run the engine until the problem is corrected.

 

[winfieldh]

Re: 1988 Johnson 150 ignition alarm question

Thanks so much Joe.

I disconnected the tan wire at the horn and the beep stopped. Also, separate effort, I disconnected the big red plug in engine box and all noise ceased. So I am concluding it is a sensor issue.

I have disconnected the oil and temp sensors, still get constant beep on second keyswitch turn to 'on'. So I'm down to VRO and fuel restriction vacuum switch. Are there any good diags/descript of where fuel vacuum sensor/switch would be and how to disconnect? I think i can get VRO.

Thanks again.
Winfield

 

[Joe Reeves]

Re: 1988 Johnson 150 ignition alarm question

The VRO.... Simply find the wires at the rear portion of the VRO, trace them back to the plug connector and disconnect it.

The vacuum switch..... observe the fuel line where it enters the pan assembly, follow that hose until you come to a tee whereas a smaller hose leads upwards to the fuel restriction vacuum switch. Remove the TAN wire from that switch.

The oil level line.... trace the lamp cord type wire from the oil tank to the plug in connector just aft of the RED electrical plug.

Disconnecting that large RED electrical pluig simply eliminates any voltage from reaching the control area so that doesn't really tell you anything with this problem.

 

[winfieldh]

Re: 1988 Johnson 150 ignition alarm question

Hi Joe,

It turns out the VRO wiring is the issue. I disconnected it and warning horn only does single chirp on multiple key 'on''s.

Looks like the vro wiring goes deeeeep, three wires directly into unit. One point, at the lake, if first key 'start' did not start engine, and key turned 'off' then 'on' (constant chirp), then 'start' and engine start/run, horn would silence and engine run fine. Kind of like, vro sensor senses no oil on second key 'on', but once engine running and oil flowing, it works properly.

This is a 3wire connection. On the pump side, a,b,c, a=tan, b=black, c=grey. There is continuity between b-c, and a-c (although less than b-c). On engine side of plug, continuity between a-b.

Not sure if any of this makes sense, but gist of it is something's up with vro wiring/mechanism. Does this make sense to tear into, or is moving to premix and disconnecting vro the way to go? Since horn stops once engine running might this imply the constant chirp on second key 'on' is an anomaly that is overcome once engine running?

Another note: While at the lake, also noticed the tach stopped working, although this chirp was happening before that too.

Thanks for help/time/guidance

W

 

[Joe Reeves]

Re: 1988 Johnson 150 ignition alarm question

The 3 wire VRO is ancient and is prone to emitting a false alarm (as you've found out). This was corrected way back with a improved 4 wire VRO.

Bottom line.... That 3 wire VRO is toast, install the 4 wire VRO as soon as possible.

The tachometer? See the following, assuming you have the water cooled voltage regulator/rectifier. This type reg/rec would be sitting on top of the engine just in back of the flywheel.

(Testing Tachometer With Water Cooled Regulator/Rectifier)
(J. Reeves)

A quick check is to simply plug in a another new tachometer as a piece of test equipment. If the new tach works properly and the old tach didn't, obviously the old tach is faulty.... but usually boaters don't carry around a spare tach (see below).

A faulty rectifier wouldn't damage the tachometer, the tachometer simply wouldn't work. This is due to the fact that the tachometer operates off of the charging system and the rectifier converts AC voltage to DC voltage, enabling the charging system. A faulty rectifier disables the charging system, and the tachometer simply doesn't register.

However.... those water cooled regulator/rectifiers that are used on the 35 ampere charging systems (and some others) bring into play a different type problem, and as you've probably found out, they are really a pain to troubleshoot via the proper procedure. There's an easier way.

The tachometer sending/receiving setup operates off of the gray wire at the tachometer. That same gray wire exists at the engine wiring harness which is connected to the engine electrical terminal strip. You'll see that there is a gray wire leading from the regulator/rectifier to that terminal strip, and that there is another gray wire attached to it. That other gray wire is the wire leading to the tachometer which is the one you're looking for.

NOTE: For the later models that DO NOT incorporate a wiring terminal strip, splicing into the "Yellow Wire" mentioned will be necessary.

Remove that gray wire that leads to the tachometer. Now, find the two (2) yellow wires leading from the stator to that terminal strip. Hopefully one of them is either yellow/gray or is connected to a yellow/gray wire at the terminal strip. If so, connect the gray wire you removed previously to that yellow/gray terminal. Start the engine and check the tachometers operation, and if the tachometer operates as it should, then the regulator/rectifier is faulty and will require replacing. If the tachometer is still faulty, replace the tachometer.

If neither of the yellow wires from the stator is yellow/gray, and neither is attached to a yellow/gray wire, then attach that gray tachometer wire to either yellow stator wire, then the other yellow wire, checking the tachometer operation on both connections.

I've found this method to be a quick and efficient way of finding out which component is faulty.... the tachometer or the regulator/rectifier. It sounds drawn out but really only takes a very short time to run through. If the water cooled regulator/rectifier proves to be faulty, don't put off replacing it as they have been known to catch on fire with disastrous consequences.

 

[winfieldh]

Re: 1988 Johnson 150 ignition alarm question

Hi again,

OK I was gearing up to disconnect VRO, reading howto's etc. After reading your post I figured I'd hunt down the tach issue first.

Well, I found the terminal strip on the stb side of engine. Took off the plastic strip cover and the terminals were all nasty and corroded. Did the sandpaper/screwdriver cleanup gig and low and behold, warning horn and tach are now both working properly!!! That led to a all around plug disconnect/terminal inspection. That was eye opening. It's a wonder any current was flowing anywhere!!

While doing that, I found another terminal block. In a plastic box bolted to rear of engine between heads. I cleaned all terminals in that, but noticed the two blocks that wires are coming out of have a black oozy type substance. It was not hot, but the black ooze was plyable. Is this an item I've got to watch or is that normal?

Thanks so much (again) for your time and effort.

Winfield

 

[Joe Reeves]

Re: 1988 Johnson 150 ignition alarm question

That black plastic box is the Power Tilt Trim relay junction box. The two blocks you mention are the relays.... one for the up mode, the other for the down mode. Iff it ever happens that the unit will function in one direction and not the other, switch relays. If the problem now reverses itself, then obviously one relay is bad.

The black ooze I think you will find is a special black insulating grease. The actual bottom portion of those relays are a hard fiberglass like material.

 

[winfieldh]

Re: 1988 Johnson 150 ignition alarm question

Joe,
Thanks for your help with all this.

Leaving well enough alone now. Hope to get to water next weekend.
Cheers.

 

[Further North]

Re: 1988 Johnson 150 ignition alarm question

Info on my search to solve a similar problem:

Found the vacuum switch...that's fine...

...went back to the oil pick up assembly on top of the oil tank...wiggled the wires a little...got a chirp...turned them a little more...the horn came on.

Must be some kind of short in there somewhere. Turned the wires so that they are running straight off the side of the tank (they were coming out of the sending unit, than kind of bent over themselves at a 90? angle), gathered up all the extra wire (must be 6 ft. of it) and zip tied it so it's not pulling the wire off to the side.

There's still obviously a short in there someplace, but now that I know what it is I'm more relaxed...can the oil pick up assembly be disassembled and the wires re-done, or am I looking at a whole new unit?