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Why is this fuse cover hot?

footbrake

footbrake

Contributing Member
Ok, first I have an 88 imperial 215 with the volvo-penta AQ231A. I happened to run into this by accident. On the dash I have a main fuse holder that powers up everything. Without this fuse nothing works. When I have my ignition in the on position to listen to the radio at the dock, in a minute the fuse holder will be very hot to the touch. If I start the engine and listen to the radio or anything else, it remains cool. what could be causing this. Something is getting very hot under there.
Secondly, I never have a problem starting or anything , yet the volt meter when running shows just 12.5 volts. I recall my other boat was always about 14.5 when running. Is the alternator on the way out maybe. Like I said though never a problem starting or anything. thanks
 
Fuse - hard to say especially with a radio wired into the ignition circuit.

The voltmeter is probably reading just what it is seeing...likely the alternator is producing over 14 VDC and there is one or more marginal connections between it and the battery.
 
without knowing the wiring of your boat i will just say this...current with resistance produces heat....remove the cover over the heat source and find out where the heat is coming from and you will probably find a problem such as corrosion etc..fix that and you may also fix your meter reading low problem....have you done any wiring changes or additions to the boat?
 
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The only things done were to wire the depth finder and vhf radio. both were done by a mechanic and wired into the dash wiring. These 2 items were turned off while the fuse holder became very warm.
 
I agree with papyson. Check the wiring and make sure the connections are tight and clean (free from corrosion), and that the wire itself is not internally corroded.
 
The wire to the fuse holder may need a larger gauge wire to carry amp load. You need to check voltage at the battery terminals, with engine running, to get an accurate reading on alternator output. Checking the voltage thru the boats wiring harness will always show a loss in voltage and differ from checking voltage at battery with engine running.
 
a problem exists at the heat source...whether its corrosion or wire too small or something wired in wrong or whatever...wiring should not get that hot..
 
Something else could be happening. If your engine has points instead of electronic ignition, you may be frying the points and the coil while keeping your ignition on without starting the engine.
 
Most boats that I have owned and worked on do not use the key switch for a power source for any accessories, etc.
These should be powered outside of the OEM hull harness and key switch, in my opinion.

I know that does not answer your question as to why this fuse is heating up. Just an FYI for you.


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Thanks. First I'll disconnect the radio from the ignition and go to the battery,fused of course. Like I said , the fuse holder only got hot with the igniton in the on position and the radio on, not while the engine was running with the radio on. I should check to see if it gets hot with the ignition in the on position and radio off.
 
footbrake said:
  1. First I'll disconnect the radio from the ignition and go to the battery, fused of course.
  2. I should check to see if it gets hot with the ignition in the on position and radio off.
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  1. Try to avoid any direct battery connections other than battery cables.

    The rear of your MBSS is a perfect location for "interruptible" power, or "non-interruptible" power.
    Terminals #1 and #2 would be "non-interruptible", and the "common" terminal would be "interruptible".
    You can bring new fresh Pos and Neg circuits forward for your accessories.

  2. Yes.
 

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footbrake said:
Thanks. First I'll disconnect the radio from the ignition and go to the battery,fused of course. Like I said , the fuse holder only got hot with the igniton in the on position and the radio on, not while the engine was running with the radio on. I should check to see if it gets hot with the ignition in the on position and radio off.
Click to expand...

You should keep the ignition in the ON position only when you are about to start the engine. Otherwise, you may ruin the points in no time and the coil could get very hot. Also, chances are that your engine hours meter (if you have one installed) will keep running while the engine is stopped.
 
kimcrwbr1 said:
  1. If you add a fuse panel under the dash like this it makes it alot easier to add accys and fuse everything.
  2. If you add an accy switch direct from the battery be sure and put a indicator light above it it is real easy to leave it on not knowing!
Click to expand...

  1. Personally, I prefer a small panel that is located away from the helm. Perhaps one like these that can be mounted in an overhead valance or in a bulk head panel.






  1. Kim, good point. However, when we pull power from the "common" terminal, this is interrupted when the MBSS is switched to OFF.
Better yet, pull this from the #2 terminal (the house bank), and if your engine harness/hull harness was to give you trouble, it can be shut down, yet we'll still have power for a GPS and VHF radio.
Add a second battery switch to cut this power when the boat is left unattended.
Anything to keep these accessories out of the engine/hull harness loop, and definitely from the key switch.


My grandfather used to say;
There are many ways to skin the cat... but the furrier dealer will tell you that some cat skinners will sell them a better pelt! :D



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