New Hunter 31 owner

[morich]

Hello all.
I recently purchased a 1985 Hunter 31 and have a few issues I could use some assistance with. The most pressing is that every time we start the yanmar the CW warning light flashes and buzzer chirps. The fresh water system seems full, the cap is on and after running for a while I can take the cap off and the water feels warm not excessively hot. What's curious is this happens immediately. Not after a while where it could be an overheating problem. Any suggestions? Thanks!

 

[IH82BL8]

I'm wondering if the water pump (not the sea water pump) isn't pumping. That would explain why the coolant in the tank is only moderately warm. Unfortunately that means the water in the engine is quite hot. You should probably get this resolved before using the engine for any significant length of time.

 

[kloudie1]

Welcome to the crew morich..
if it is cooling water and not oil pressure, you may have a short to ground in the wiring or a bad thermal switch.. After you first start it, pull the wire off the switch .. if the beep stops, it is a bad switch.. if it continues, it is a short to ground in the wires or connectors between the engine and the panel.
To clarify, you're not talking of the normal beep that happens as soon as the key is turned on, right? and goes away soon after (2 seconds) the engine cranks?

 

[morich]

Thanks for your response. Although it is the same speaker, it is not the same buzz sound when you first turn the key on. This is more like a bird chirp. Sometimes stops briefly when rpm goes to idle. I'm thinking its an electrical issue since it happens immediately. Can you tell me where the sending unit is located on the engine? I can't seem to find it. The only one I see is the oil pressure one right next to the oil filter. Thanks again!

 

[Steve Dion]

Check the connection on the engine. We had the connection almost broke off on our 2Gm on our H'31. Purchased a new sending unit and it was fixed.

 

[morich]

Hi Steve. Where is this unit located? I can't find it. Thanks!

 

[morich]

Hi Steve. Where is this unit located on the engine? I can't seem to find it. Thanks!

 

[Steve Dion]

I think this is the water temp sensor.

 

[Bill Roosa]

If the buzzer is the same for oil and water (and alternator too BTW) then it should sound the same for all alarms unless there is a different ground. They all work by a switch grounding the circuit. If we assume that all the switches are "really good grounds" the sound would be the same. If your hearing a different sound then the ground is not being made by a switch and one of the ground wires that run to the switches is going bad. I'm betting that since it goes off at idle on occasion and it sounds different (not grounding well???? does it "sound weak?) that it is one of the wires.
If you pull the WT switch wire off and the buzzer still sounds then it is surly the wires grounding. If the WT light is lighting then that circuit is the problem child. Follow the wire from the switch along the engine to find where it has chafed through.
You can do this with the engine off if you first pull the oil pressure switch wire off its switch.
and welcome aboard.

 

[morich]

Thanks Bill. Yes, it sounds much weaker than the start alarm. I'm not quite sure where the temp sending unit is located on the engine. Another member, Steve Dion sent me a picture but either I'm worse than I think or my engine is different. i have a 2GM20F engine in the boat. The CW light flashes on and off. Not with any steady patern. I'm thinking along the same lines. That its an electrical issue. If only I can find that sending unit I can begine the troubleshooting process. Thanks!
Pulling the oil pressure switch wire... was that a typo? I don't see the connection. Thanks!

 

[wufibugs]

Steve has it correctly circled. It may be that the "cap" on the wire is gone so it looks different, but that's where it is. All the wiring between the engine and the cockpit instrument panel runs into the starboard locker and then through the wall between the locker and the aft berth, and under the pedestal to the panel. If the temp sender wire is shorting, it is most likely to be in the engine compartment or at the cockpit panel. The H31 was not handsomely wired and was very short on shrink tubing.

 

[kloudie1]

Temp switch, 2 GMF

Morich, on your 2GMF, the switch is just below the thermostat housing, probably just aft of the hoses that go to the water heater. These pictures are of a 3 GMF, but the front of your engine looks pretty much the same. The switch is behind the top most belt pulley and kinda hidden behind the hose with the green stripe on my engine.
It sounds like you have a bad wire somewhere between the engine and tachometer panel.. have you tried wiggling the switch on the panel? that switch turns the lights on when pushed one way, and checks the alarms when pushed the other.. The chirp you are describing sounds like an intermittent ground of the alarm circuit.

 

[kloudie1]

Yanmar Wiring

Morich, here is what the wiring diagram for your engine probably looks like.. The wire is a white/blue and probably has been painted as mine is.

 

[seadaddler]

Exhaust

What does the exhaust water flow look like and is water being expelled out the exhaust.
I forget where but saw once that a ohms test can tell if the temp and oil senders are good and working properly maybe on the yanmar site.
Nick

 

[morich]

Thanks Nick. Two things... how can you tell how much water flow you have? My Hunter 27 exhaust came out the transom. This one comes out the bottom so I can't tell how much flow I have.

The issue seems to be electric because it starts as soon as the engine starts up. I'm leaning more and more toward a ground because it sometimes goes away when I adjust the RPM. As if it makes its connection and then looses it again. Still not sure.

To boot, this guy disconnected the CW sending unit. I see a wire coming out from the harness, gets looped over the alt bracket, has an in-line fuse in it and then goes back to the harness. Have no idea if this is in any way, shape or form related to the problem. Jus makes me suspicious.

Now that I have the wiring diargram printed out Im going back to the boat with my trusty Fluke gauge and I'll try to resolve this. But then... I have a list of other issues with the boat I'd love to get some help with. Thank you all for the tremendous amout of help and information. I was completely without a clue. Now I have a path to go down. Thanks again!

 

[morich]

Re: Temp switch, 2 GMF

Hello again.
Thank you everyone who took the time to help me with this problem. With your guidance, pictures and wiring diagrams I was able to resolve this problem. In fact, the PO disconnected the temp sensor. That's the reason I couldn't find it. He had a plug there instead. I found the wire, with the end of the sensor still attached lying on the port engine mount support. So simple, yet so difficult if you don't know what You're looking for. Thanks again!!!
I'm going to put out a new post. The PO removed and threw away all the lexan(?) doors for the shelving units. I want to replace them. Hunter has no info on sizing and or knowledge of what material they are. Any info on where I might go for these would be much appreciated. Thanks!