water temp alarm

[Rob Haas]

Electrical Issues Mechanics prespective

Many weird electrical problems can be associated to Ground connections. People very frequently over look the fact that the grounds have to be just as good as the positives or user wires. It will cause normal circuits to seek out a ground through any component they can find it in. I would double check all ground connections to your instrument cluster. Does your wiring harness have a plug at the engine? Take it apart and look for green corrosion or signs of even black traces of arcing on the spade or pin connectors. If they do not fit tight you can tweek the connectors with needle nose. Clean them first. The other thing that comes to mind is if you have an overheat alarm it is probably also tied into the oil pressure for low oil pressure alarm. Most of these systems are not activated until the alternator is charging. So there is a couple of more items to check out with out spending money.

 

[Rob Haas]

Electrical Issues Mechanics prespective

Many weird electrical problems can be associated to Ground connections. People very frequently over look the fact that the grounds have to be just as good as the positives or user wires. It will cause normal circuits to seek out a ground through any component they can find it in. I would double check all ground connections to your instrument cluster. Does your wiring harness have a plug at the engine? Take it apart and look for green corrosion or signs of even black traces of arcing on the spade or pin connectors. If they do not fit tight you can tweek the connectors with needle nose. Clean them first. The other thing that comes to mind is if you have an overheat alarm it is probably also tied into the oil pressure for low oil pressure alarm. Most of these systems are not activated until the alternator is charging. So there is a couple of more items to check out with out spending money.

 

[Stu Jackson]

The panel voltmeter pegged with the engine

off, John. So the alternator shouldn't be an issue. I'm glad to hear it was dry behind the panel. What the next steps should be are to check the grounds, as we discussed and as Rob suggested. If you need a good electrician, try Ryan Schofield, he advertises in the back few dozen pages of Latitude 38, Schofield Marine. He's very good, a number of my friends have used him and he's at the Oakland Yacht Club or Marina Village, not far away.

 

[Stu Jackson]

The panel voltmeter pegged with the engine

off, John. So the alternator shouldn't be an issue. I'm glad to hear it was dry behind the panel. What the next steps should be are to check the grounds, as we discussed and as Rob suggested. If you need a good electrician, try Ryan Schofield, he advertises in the back few dozen pages of Latitude 38, Schofield Marine. He's very good, a number of my friends have used him and he's at the Oakland Yacht Club or Marina Village, not far away.

 

[John]

I took a cursory look

at the grounds on the engine when I was on the boat this morning. It would seem to me that since the gauges only started acting weird after I changed the coolant, that it's likely related. What makes sense to me (with the little knowledge I have) is that some of the coolant that ran out of the engine shorted out something - maybe a ground. I'll go back and double check.The other issue is that I now have no AC with the shore power hooked up. At least that was the case a few days ago; I didn't double check it today.

 

[John]

I took a cursory look

at the grounds on the engine when I was on the boat this morning. It would seem to me that since the gauges only started acting weird after I changed the coolant, that it's likely related. What makes sense to me (with the little knowledge I have) is that some of the coolant that ran out of the engine shorted out something - maybe a ground. I'll go back and double check.The other issue is that I now have no AC with the shore power hooked up. At least that was the case a few days ago; I didn't double check it today.

 

[Maine Sail]

John...

Like your compass trust your meter! I don't mean your volt meter on your boat I mean your Fluke digital multimeter or what have you.Turn the key on and connect the leads to the back of the volt meter. It should read somewhere between 12.0 and 12.6 volts without the engine running or the shore power charging. If the meter (Fluke type) says the right voltage range is coming from the batteries then you have a problem with your boats volt meter which could be as simple as ground. Unfortunately this ground scenario is doubtful if the meter is pegging with only 12 or so volts coming into it...

 

[Maine Sail]

John...

Like your compass trust your meter! I don't mean your volt meter on your boat I mean your Fluke digital multimeter or what have you.Turn the key on and connect the leads to the back of the volt meter. It should read somewhere between 12.0 and 12.6 volts without the engine running or the shore power charging. If the meter (Fluke type) says the right voltage range is coming from the batteries then you have a problem with your boats volt meter which could be as simple as ground. Unfortunately this ground scenario is doubtful if the meter is pegging with only 12 or so volts coming into it...

 

[John]

2 meters

I also have a voltage meter over the nav station - where the electric panel is. This meter reads about 12.6 volts when I push the "test" switch and the batteries are turned on. When the batteries are off, it reads zero. This is why I suspect it's some connection away from the battery. Also, as I said, I'm trying to figure out why the AC power wouldn't work either.

 

[John]

2 meters

I also have a voltage meter over the nav station - where the electric panel is. This meter reads about 12.6 volts when I push the "test" switch and the batteries are turned on. When the batteries are off, it reads zero. This is why I suspect it's some connection away from the battery. Also, as I said, I'm trying to figure out why the AC power wouldn't work either.

 

[Ross]

All volt meters are milli or micro amp meters

that have a resister in series in them. If the resister gets shorted (partial shorts are enough) then the meter reading will be off. Connect your "fluke" across the posts on the built in meter with the power on and check that.

 

[Ross]

All volt meters are milli or micro amp meters

that have a resister in series in them. If the resister gets shorted (partial shorts are enough) then the meter reading will be off. Connect your "fluke" across the posts on the built in meter with the power on and check that.

 

[John]

Finally (I think)

I think - I hope - that I've finally got most of my problems resolved regarding these issues. First of all, regarding the fact that my AC power wasn't working: It helps to check the circuit breaker on dock's outlet. (Duh!) I then checked the temp gauge and the voltage gauge with a multimeter. The multimeter registered nothing on either gauge with the key and/or the battery turned off. Yet the battery gauge showed about 8 volts with everything off. I figured that the most likely was that the gauge was no good, and I figured this was the perfect use for the $50 certificate from West Marine that I had (from a promotion they were running in December). After installing the gauge and cranking up the engine, it seemed to be fine, although it does register a little high (about 15.5 volts). I'm thinking this might be because the batteries have run down a little.As for the hot water temp alarm going off: I got the infrared thermometer as was suggested ($22 from Cabellas. com) and tested the temp gauge. The infrared thermometer registered the same temperature as the gauge did. So I changed the sensor for the alarm. This seems to have solved the problem since the engine now heats up without the alarm going off. One issue that still remains is that it still runs a little cool (a few degrees below 160). I just put in a new thermostat, but I'm going to take it out and test it in a pot of hot water to see at what temperature it opens up.Thanks to everybody for their suggestions on this issue.

 

[John]

Finally (I think)

I think - I hope - that I've finally got most of my problems resolved regarding these issues. First of all, regarding the fact that my AC power wasn't working: It helps to check the circuit breaker on dock's outlet. (Duh!) I then checked the temp gauge and the voltage gauge with a multimeter. The multimeter registered nothing on either gauge with the key and/or the battery turned off. Yet the battery gauge showed about 8 volts with everything off. I figured that the most likely was that the gauge was no good, and I figured this was the perfect use for the $50 certificate from West Marine that I had (from a promotion they were running in December). After installing the gauge and cranking up the engine, it seemed to be fine, although it does register a little high (about 15.5 volts). I'm thinking this might be because the batteries have run down a little.As for the hot water temp alarm going off: I got the infrared thermometer as was suggested ($22 from Cabellas. com) and tested the temp gauge. The infrared thermometer registered the same temperature as the gauge did. So I changed the sensor for the alarm. This seems to have solved the problem since the engine now heats up without the alarm going off. One issue that still remains is that it still runs a little cool (a few degrees below 160). I just put in a new thermostat, but I'm going to take it out and test it in a pot of hot water to see at what temperature it opens up.Thanks to everybody for their suggestions on this issue.

 

[Maine Sail]

Thermostats..

Thermostats re not exact or all that accurate. The 160 degree rating is most likely +/- 1-8 degrees in reality depending on your individual stat. Some are more exact than others but I've seen them off by up to eight to ten degrees. I would not worry if it's only a few degrees off. If it's 15+ I'd begin to worry but I've yet to see a thermostat that says 160 or 180 actually maintain exactly 160 or 180. How far off is it from the reading you get while shooting the thermostat housing above and below the stat and what the gauge says?Oh yeah and the gauges / sending units are also not all that accurate either. Frustrating, I know, but that's why you now have an infrared!!

 

[Maine Sail]

Thermostats..

Thermostats re not exact or all that accurate. The 160 degree rating is most likely +/- 1-8 degrees in reality depending on your individual stat. Some are more exact than others but I've seen them off by up to eight to ten degrees. I would not worry if it's only a few degrees off. If it's 15+ I'd begin to worry but I've yet to see a thermostat that says 160 or 180 actually maintain exactly 160 or 180. How far off is it from the reading you get while shooting the thermostat housing above and below the stat and what the gauge says?Oh yeah and the gauges / sending units are also not all that accurate either. Frustrating, I know, but that's why you now have an infrared!!

 

[John]

thermostat & infrared

yes, I checked the temp gauge against the infrared thermometer. They both read close to the same; I think the infrared thermometer showed a few degrees cooler, but then it is aimed at the housing and the sensor is actually in the coolant. But in any case, I'm pretty confident that the temp gauge is giving me a pretty accurate reading.

 

[John]

thermostat & infrared

yes, I checked the temp gauge against the infrared thermometer. They both read close to the same; I think the infrared thermometer showed a few degrees cooler, but then it is aimed at the housing and the sensor is actually in the coolant. But in any case, I'm pretty confident that the temp gauge is giving me a pretty accurate reading.