Engine blower not working

[B4A]

One of my engine blowers stopped working. If I test it with a multimeter, with the Power On, I get this.

What should I do next for troubleshooting the issue?

[Dockhead]

I think this is very simple --


If there's power getting to it, and it doesn't work -- toss it. That's all the troubleshooting you need to do.



Those things have limited life and are not user serviceable. My expensive Jabsco one died almost to the hour at its rated 3000 hour life. I had to have a new one shipped into the Faro Islands last summer.


When you replace, choose carefully -- engine room blowers need to be higher hour rated than intermittent use blowers. There is a big cost difference, but you get what you pay for.

[Bill O]

A little hard to tell from the pic, but it looks like you are testing the power/wires coming from the panel(?) and you have basically no voltage to run the blower.
How about at the switch/panel do you have power there? Bad breaker? If power at the switch, then bad wiring to the blower. Check for continuity on each line (power & grd.).
We just had a blower go down but we had power to the motor. Replaced the blower and working fine.


Bill O.

[Dockhead]

Oh, and buy two. The other one will go out too, soon enough.

[B4A]

So when I check the voltage at the wires going to the blower my multimeter reads only 0.053 volts.

I checked the 10A blade fuse in the Junction box and I have continuity.

So the question is how come the voltage delivered to the blower is so low? What should I check next?



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[Cheechako]

That reading is likely some stray current. You dont have power to the blower. Check fuse, wire, ground etc. Often ground wires get corroded and lose continuity. Follow that wire and look at any connections/joints in the wire.

[Bill O]

You'll need to work backwards to see where you are losing power. Use a separate grd/or a known good grd and check at the fuse and panel switch. Breakers do go bad.

If you have power coming out of the switch, then you need to check the wires to the blower. The check for a broken wire check both power and grd wires separately for continuity (from switch to blower).


Bill O.

[guyrj33]

i suggest pulling the fuse out of the holder and then checking for continuity.
I can't see where your black lead is going from the multi-meter when you have the red lead shoved in the fuse holder.

I'll also suggest getting a good book on 12v systems, 12 volt bible is one that comes to mind.

finally Ohm's law V=R*I is your friend,
Voltage = Resistance(ohms) x Current(amps).

[Emouchet]

Run 2 wires directly from the batteries, for testing the blower.
If it runs, then you know it is a wire issue.
If it does not run, then the blower is dead.

[mynameismud]

The .005 is just stray current. Next see if power is at the switch, if power trace that side to blower.

[romel]

The engine blower on my Jeaneau Sun Odyssey has a thermostat that runs on one of the power lines. (Not sure if its the positive or the negative now) So the blower only comes on when the engine room temperature rises above the preset value of the thermostat (usually after 20 minutes or so of motoring) and will stay on till the temp comes back down. The blower runs independently of the engine circuit so that it will stay on even with ignition key turned off. I prefer it this way as it helps cool the boat down when I get to an anchorage. Normally the blower will stay on 15 to 20 minutes and cycles off /on several times after the engine is turned off as the engine radiates heat. Understandably ambient temperature makes a lot of difference. This difference is easy to notice in winter as the fan will take longer to start and is quicker to turn off.
In my experience the fans (even the name brands) do not last longer then 2 to 3 seasons. So the last time I replaced with a much cheaper unbranded one which has been there for 2 seasons now. In that time I have never had a problem with the thermostat. I check the thermostat by blowing a hot hairdryer on it to simulate a hot engine room. Do make sure there are no fuel fumes in the engine compartment before starting a hair dryer.
If you supply the motor with DC directly from a battery and it runs OK then start following your power supply lines.
Hope this helps
Ron

[Bill Seal]

It's obvious your engine room is waaay too clean, and the electrons are just sliding off that shiny surface.

[thunderhoof]

You may have a broken / corroded wire from panel to blower. Try measuring from the positive fan terminal to a known negative point like the battery (-) terminal and vice versa. if you see 12 v in either case you will know where the faulty wire is.

[Alita49DS]

Put away that meter and do what Emouchet advises.

My money is on the blower. In my experience the only thing expensive about them is the purchase price. Otherwise they are cheap rubbish and you should always carry a spare.

[captlloyd]

Originally Posted by Emouchet

Run 2 wires directly from the batteries, for testing the blower.
If it runs, then you know it is a wire issue.
If it does not run, then the blower is dead.

There you go !