HWH wow's

[tiredvet]

I was lowering the jacks while looking in the hydraulic bay and I noticed the 40 amp fuse holder smoking. The fuse never tripped and the jacks all lowered I shut the system down and had a rough time removing the fuse. When the fuse came out one of the fuse spades had welded it's self to the connector.I'm hoping that just the fuse holder was bad or am I wishful thinking? I'll need a new 40 amp fuse holder and fuse at least.

[Statgeek]

Yikes!! That's some scary you-know-what! I'm following just to see if this has happened to others... and yet another thing that I need to keep me up at night. Smoking 12v gives me the heebie jeebies..

[Algoma]

Those fuses are subject to abuse from road spray and I have replaced mine because they were badly corroded. You need to replace the holder and get one that is waterproof.

[Iwillbeit]

I bet you will be fine with a holder and fuse. If the fuse don't blow, that means the current was still under the 40 amp it's rated at. I won't rule out it could have a bad fuse letting more tan 40 amps go through, but highly unlikely. My guess is the fuse connection was corroded or loose, causing resistance leading to heat buildup or arcing.

Randy

[tiredvet]

I'm finding it hard to find 40 amp fuses and I read where they are no longer available? I found one that will take up to 35 amp but it is 12 ga wire and I'm not sure what ga wire is on my existing fuse holder. John what did you use for your holder replacement? After watching mine smolder and thinking that area is one of the last places to have a fire I want to be sure not to under size the wire.

[tiredvet]

Originally Posted by Iwillbeit

I bet you will be fine with a holder and fuse. If the fuse don't blow, that means the current was still under the 40 amp it's rated at. I won't rule out it could have a bad fuse letting more tan 40 amps go through, but highly unlikely. My guess is the fuse connection was corroded or loose, causing resistance leading to heat buildup or arcing.

Randy

I'm leaning that direction to Randy.I just need to find the best water tight fuse holder and amp fuse for a replacement.

[tiredvet]

Well after looking on flea bay I found plenty of 40 amp large blade fuses. So I need to come up with a matching holder.

[Mike & Mike]

Hi Jim,

I've got a couple of suggestions for you. It seems that 'motorhomes' and 'boats' have a lot of parts or systems in common. I've always found the West Marine stores (and website) to be quite the toy store for the motorhome owner. I see that there's one up in Spokane Valley, not too far from you. They have stores all over.

Blue Sea is a manufacturer of electrical components for boats and they have a 30 amp waterproof fuse holder at West Marine: BLUE SEA SYSTEMS In-Line, Waterproof Fuse Holder at West Marine

There s a fuse block at the Blue Sea website that's good for up to 80 amps, though not waterproof: MAXI Fuse Block - 30 to 80A - Blue Sea Systems

Good luck!

[Algoma]

Originally Posted by tiredvet

I'm finding it hard to find 40 amp fuses and I read where they are no longer available? I found one that will take up to 35 amp but it is 12 ga wire and I'm not sure what ga wire is on my existing fuse holder. John what did you use for your holder replacement? After watching mine smolder and thinking that area is one of the last places to have a fire I want to be sure not to under size the wire.

It's been a while so can't remember which holder I used. This one from NAPA is not totally waterproof but has a moisture resistant cap so should be adequate. You are using only a short length of the 12 gauge wire and are not running the pump continually so I think you will be OK with a 40A fuse. I think this comes with a 30A fuse. Here is an alternative I found on Amazon that is waterproof.
One of these days I will measure the current on this wire and see if 40A is really needed.

[EngineerMike]

Some interesting fuse-sizing facts, just for fun:
1) fuses are sized to protect insulation on the wire in the circuit.
2) fuses are sized by the mfgr of the device served, as their engineers are presumed to be the most knowledgeable about the exigencies of the circuit
3) fuses (and wire size) should be oversized for ordinary operating conditions of the circuit to account for spikes or transients that would occur above the steady-state operating amperage, and then a bit more to eliminate nuisance fuse blowing. The amount of oversize is up to the circuit engineer. Since this results from some calculation, empirical experimentation, etc., it will likely result in an odd fuse size number on paper, e.g. 36.3A, which is rounded up to the next regular fuse size of 40. Then the rest of the circuit is supposed to be checked to see that 40A wire & fuse comports w/the circuit w/out issues.

FWIW, the HWH compartment does not need all the breathing capacity it has. Many folks have sealed the compartment w/expanding foam at the hose exit hole in the frame, aluminum tape over holes, etc., to limit the amount of road spray & filth that accumulates in the compartment. This makes service & diagnosis dramatically easier when it happens. For those w/their HWH motherboard beautifully facing the small HWH door behind the RF wheel, when you take the motherboard off its frame for easier access sealing the compartment, saw off the top of the frame just above the cutout for the metal clips on each side; the top of the frame is superfluous and its only discernible function is to be in the way. Also, mark the connector positions carefully; there are two like connectors that can get confused, and its easier to mark them than puzzle out which one goes where.

[EngineerMike]

Jim-
Search eBay for a 10Ga inline blade type fuse holder. Should be plenty for ~$5.
Then head into NAPA & get the standard size 40A fuse. there are Mini & Maxi fuses as well as standard, best to stick to the standard.

IIWMI'd clip out the OEM 40A fuse holder, butt connect extensions (10Ga) onto both legs using marine type glue-heat seal butt connectors, then ditto on the new 10Ga fuse holder, placing it into a location that I can inspect it when the HWH system fritzes out. Then I'd put my spare 40A blade fuse(s) into a small zip lock baggie, & zip tie them to the new 40A fuse holder for safe keeping where I know I can run into them if I need to replace this fuse.

[tiredvet]

Thanks to all and a special thank you to zinom A.K.A Matt for sending me a waterproof 40 amp holder (10Ga) that he had left over from an electrical project. I hope to get this project handled after turkey day, (off to Oregon to stuff ourselves). It's days like today that I envy so many of you that are in warmer parts of the country, It dumped 9" of snow last night! dag nab-it.

[Renipladlo]

For all - Take the time to check that all the fuse's have some kind of dielectric grease on them. You can use WD-40 in a pinch, but Eoff's and other stores sell dielectric grease. I use NO-OX-ID- Special A, it's a product used in the high voltage electrical industry, it comes in half pint cans, and it will last you the rest of your natural life. I treat every connection I come into contact with and have never experienced your issues. I also did this on my bass boat, and never had any electrical issues with it. I have the Modified 625 system, and an APEX, so WRV did this one a little different. Taking the time to coat those connections and fuse holders will prevent this from happening again.

TIP #2, for those with the "elbow hinge" on the main door which lock it open with a spring clip, putting the above on it, will also keep water for rusting out that little spring, as the part needs to be replaced in whole at around 80 dollars for the new elbow part, I do that once a year or when I am doing other stuff when I have my can of stuff out.