Blower and Bilge Pump not working

[bigred55]

I have a Mercruiser 3.0 OW380726 on a 2006 Bayliner 175. For some reason it isn't allowing me to view my other topic so I'll start a new one. I've checked the fuses on both switches and they look fine. I can't find where the blower is and I can't seem to twist the bilge pump off of the base. I think the next step is to see if I'm getting 12V at each pump but I don't know what to hold each probe on to check.

 

[alldodge]

The blower is usually under the gunnel, look for the vent hose (resembles latex dryer vent hose). You need a volt meter to check for 12V. A volt ohm meter would be better to check across the fuses to determine if they are blown. The bilge wiring should come straight from the battery, and in most cases go through the float switch first. If you lift the float switch will the bilge pump turn on?

 

[bigred55]

Do all bilge pumps have a float switch? I don't think mine does. I unscrewed the 3 screws holding it down then removed the base and all it has is the hole for the little impeller. Which I can't get a finger inside to move it, but the end of a screwdriver turns it not as smooth as silk but with little resistance

 

[bigred55]

Ok I've got the bilge pump and blower disconnected. Now I just need to know which probes on voltmeter go where for each test. Thanks

 

[bigred55]

Also the 2 bilge wires aren't hooked directly to the battery

 

[stonyloam]

OK first things first. You need to check for voltage at the back of the switches. Since both the bilge pump and blower work with the ignition switch off you need to find out if you have 12 volts going to each of the switches. Look behind the dash for the terminal on the switch, there should be a purple, red or orange wire. Put the red probe of the voltmeter on the terminal and the black probe on ground. Look for a black wire coming off of the tach or one of the other gauges for ground. If you do not find 12V on the switch , you have an open circuit between the switch and the ground, and your pump and blower are probably OK.

 

[kjsAZ]

If you have a DVM it is simple as it doesn't really care about polarity. Connect one tip to one wire and the second one to the other one. If you read a negative voltage you just got the probes reversed but you know the voltage is there. Same for blower and bilge pump.

Bayliners (small ones) never came with a float switch but they should have one. They are connected to "ground" on one side (naturally). The other side comes from the fuse block and goes via the switch in the helm to the to the pump.

The blowers usually used in smaller boats are a joke to start with. These inline (or turbo) blowers are best in converting power into noise and not into airflow and have a very short lifespan. If you run them for 30mins they overheat and die. Their only key feature is the price point.... Better replace it with a continuous duty squirrel cage fan. Quiet, a lot more volume and they last forever. My favorite are the SPX-Johnson ones. http://www.spx.com/en/johnson-pump-m...-blowers-airv/ . A bit more work to install them but you don't have to do it again in a year or two...

 

[bigred55]

The only color wires I see at the back of each switch are 2 gray wires attached to bilge switch and 3 black/yellow wires attached to blower. There is an orange/black but it goes to accessory. I know virtually nothing about wiring so if there's anyway to dumb it down anymore please do. I have a craftsman digital multimeter that can be set to volts or ohms. I don't know what to look for if it is set at ohms. And I'm still lost on where to stick the red and black probes to test. Thanks

 

[kjsAZ]

forget the ohms for now and concentrate on volts. Measure from a "ground" wire to both sides of the switches. If you have voltage on one side and none on the other turn the switch on and you should have voltage there too. Voltage has to be the same (almost) as the battery voltage which means anything between 11V and 14V is good for now.
Black lead goes to "ground" and red to the point you want to probe for voltage. Most likely the ground wire in your helm is a yellow wire as that was chosen for marine ground for some strange reasons. However, I have seen the more standard black there too. Bayliner usually uses yellow.

 

[bigred55]

Any yellow wire will work for the ground?

 

[kjsAZ]

well, it all depends whether a previous owner ran havoc in there or not. Look at the lights for the gauges as they are powered with 12V. If they have a yellow wire at one side this is a good one.....

 

[bigred55]

No yellow wire connected to lights

 

[kjsAZ]

any black one?

 

[bigred55]

No, just blue, gray and blue and gray and red. I tried to upload a picture but it says the size is too big

 

[kjsAZ]

OK, we have to go back to basics..... Plug the black probe into the common terminal of your DVM and the red one in the volt socket. Take your DVM set to measure voltage and hold the two probes at both sides of the gauge illumination bulb. Make sure that you turned on the backlight of the gauges. If you read +12V (anything between 11V and 14V) ground or minus is where your black probe is. If it reads minus the ground is where the red probe touches. Now you have your ground wire....