Bad HWH Main Fuse…

Back in late June 2018, I arrived at an RV park in Wendell, ID and strangely, nothing in my hydraulic system worked! I’d been able to retract the slides and jacks the morning I’d left to get here but when I arrived and paid for a week than drove to my assigned space, tried to extend the jacks and nothing. No noise at all from the hydraulic motor as was typical. So I tried the slides as they also use the HWH hydraulic system. Nothing. Quiet.

Well, one of the reasons I wanted to buy this style of RV was because I could still live in it without extending the slides. Or the jacks. So I got comfortable and did some searches in the many pages of RV books and files I have on board and on my computer. Took several hours to discover that there is a large 40 amp fuse somewhere in the HWH system. And it supplies power to everything in that system. So if it’s blown, nothing works. I pulled the HWH box under the dash, but no 40 amp fuse there. And no voltage getting to it either.

So a couple days later, opened the basement compartment door under the rear of the living room slide, and there I have an excellent view of the HWH hydraulic manifold. Noticed a bunch of rats nest wiring around and above it. So started searching in that mess. Took around 2 minutes of pawing through the rats nest of wiring around the manifold but eventually, found the problem…

Here’s a shot of the manifold AFTER I discovered that the old fashioned inline automotive fuse holder (a large one for a large cartridge type fuse) had corroded enough that it sort of fell apart. I found it just loosely hanging by wire threads. Well now, that could certainly cause the problem.

So here’s what I did to repair it. I drove over to the nearest Napa auto parts store and found their ‘generic’ automotive parts rack, found a large 40 amp fuse but it had spade lugs.  They did have the old timey inline fuse holders but not the large size. Well, no problem as I carry spade terminals that will fit right on this modern 40 amp fuse. I thought. Turned out all I had were for 1/4″ but these lugs were 5/16″ so large terminals were needed by the new fuse.

So back to Napa to purchase a pack of them. And as you can see, I did have the tool to crimp them onto the stripped back wires (I’d cut them back beyond the corrosion), and the heat shrink tubing to cover them. So now it’s 2023 and I’ve not had to do a thing to this setup since. It’s still doing well and the slide and jacks have worked fine…er, well, they’ve always had power anyways.