I am experiencing a problem with my HWH Jacks. The jacks operate fine, raise the coach, retract with no issues. But upon retracting (pressing the store button) the inline 40 amp fuse holder (by the pump) completely melted and was smoking. Called HWH and they said to replace the corroded fuse holder. I removed the melted fuse holder, replaced with only a new 40 amp blade fuse to observe. When raising the jacks, the wires and fuse itself stay completely cool. But when pressing the "STORE" button, the jacks retract, but the wire and 40 amp fuse itself get very hot. Fuse does not blow, but the fuse and connectors are very hot. Anyone have an idea on what the problem could be? I don't want to simply replace the fuse holder, because I think it will likely just melt again. seems to be a problem somewhere, but I don't know where to look next.2001 Itasca SuncruiserHWH Model 310 Leveling jack system.

There's a lot of resistance right where the heat is.

In STORE, the only real draw is the 4 solenoids. The solenoids used to be on 4- 10 amp fuses. 1- 10 amp per solenoid. What your problem points to, is, something in store is pulling excess current. The solenoids operate the same in extend. So, you need to observe if that fuse holder gets HOT like it does in store. I will bet it does. Your problem is, you NEED to replace the fuse holder. It has been compromised by the previous failure and THAT will cause resistance and heat. I would also disconnect each solenoid 2 wire quick connect 1 at a time and see if one of the solenoids is causing the heat. You could also disconnect all 4, hit store and see if the wire gets HOT. If NOT, then 1 of the solenoids is failing. Do NOT run in store more than 10 minutes. Those solenoids cannot withstand a constant power to them. After 15 to 30 minutes the coils WILL overheat and destroy the solenoid/s. Doug

A pic would help. The resistance could be where there's a connection to the fuse holder, a crimp or the holder itself.

does this system use a single 'dump' valve for all jacks ?its 'odd' that you can run a pump and multiple valves while 'extending' the jacks to levelbut blow a fuse on retract, when the only load is open one or more valvescould the power control wire for the dump valve be shorted, or the dump valve coil be bad, it should be getting hot if it is blowing that 40 amp fusei would check those coils for 'excess' heat

Still working on this. The 40 amp fuse does NOT blow. I am using a blade fuse labeled 40 amp ATC. Is that the right type of fuse? If I put in a 15 amp fuse, it will blow when I press Store, but it does not blow the 40 amp fuse.I cleaned up the connectors and made them tight on the fuse. It seems the fuse and connectors now get fairly warm, but not scorching hot as before. But the 40 amp fuse does not blow. Want to make sure I am using the correct type of fuse. I don't know ATC from ATO type fuses

HWH Fuse holder melted - wire gets hot when storing jacks

ScottG
Nomad
Apr 08, 2018
There's a lot of resistance right where the heat is.
dougrainer
Nomad
Apr 08, 2018
In STORE, the only real draw is the 4 solenoids. The solenoids used to be on 4- 10 amp fuses. 1- 10 amp per solenoid. What your problem points to, is, something in store is pulling excess current. The solenoids operate the same in extend. So, you need to observe if that fuse holder gets HOT like it does in store. I will bet it does. Your problem is, you NEED to replace the fuse holder. It has been compromised by the previous failure and THAT will cause resistance and heat. I would also disconnect each solenoid 2 wire quick connect 1 at a time and see if one of the solenoids is causing the heat. You could also disconnect all 4, hit store and see if the wire gets HOT. If NOT, then 1 of the solenoids is failing. Do NOT run in store more than 10 minutes. Those solenoids cannot withstand a constant power to them. After 15 to 30 minutes the coils WILL overheat and destroy the solenoid/s. Doug
ScottG
Nomad
Apr 08, 2018
A pic would help. The resistance could be where there's a connection to the fuse holder, a crimp or the holder itself.
MrWizard
Moderator
Apr 08, 2018
does this system use a single 'dump' valve for all jacks ?

its 'odd' that you can run a pump and multiple valves while 'extending' the jacks to level

but blow a fuse on retract, when the only load is open one or more valves

could the power control wire for the dump valve be shorted, or the dump valve coil be bad, it should be getting hot if it is blowing that 40 amp fuse

i would check those coils for 'excess' heat
kmb1966
Explorer
Apr 08, 2018
Still working on this. The 40 amp fuse does NOT blow. I am using a blade fuse labeled 40 amp ATC. Is that the right type of fuse?
If I put in a 15 amp fuse, it will blow when I press Store, but it does not blow the 40 amp fuse.
I cleaned up the connectors and made them tight on the fuse. It seems the fuse and connectors now get fairly warm, but not scorching hot as before. But the 40 amp fuse does not blow. Want to make sure I am using the correct type of fuse. I don't know ATC from ATO type fuses
ScottG
Nomad
Apr 08, 2018
The difference is ATC fuses are sealed and ATO isn't. So in a clean, interior environment the cheaper ATO is fine but otherwise, the ATC is best.
There is no other functional difference.
time2roll
Nomad
Apr 09, 2018
Is 40 amp the proper fuse? (appears correct according to Doug)

Maxi fuse holder: http://www.genuinedealz.com/maxi-fuse-inline-fuse-holder-w-6-awg-leads-up-to-60a
Not going to melt at 40 amps.
brulaz
Explorer
Apr 09, 2018
In a similar "hot fuse holder" situation, I removed the fuse holder and upgraded it to a higher quality one.

That Maxi fuse holder linked above with a 40A Maxi fuse will prolly do the trick.

I take it the wires some distance from the fuse/holder remain cool?
kmb1966
Explorer
Apr 09, 2018
time2roll wrote:
Is 40 amp the proper fuse? (appears correct according to Doug)

Maxi fuse holder: http://www.genuinedealz.com/maxi-fuse-inline-fuse-holder-w-6-awg-leads-up-to-60a
Not going to melt at 40 amps.

This is what I ordered. Now, any ideas on how I connect this in?
Do I crimp connectors on each end or do I splice the wires together? solder? how could I get it connected so that it is tight so less heat/resistance?
dougrainer
Nomad
Apr 09, 2018
https://www.hwhcorp.com/ml13514.pdf

The 40 amp fuse supplies the silver control box IF you have the 2001 model still. It goes to the control box(wire 6100). AT the control box is a 1/4 inch stud that a large gauge (10 gauge) ground wire is secured to that stud. IF that ground wire is not secure or the ground feed from the chassis source is weak/corroded, THAT will cause that type heat and failure on the 40 amp fuse. Pages 27 thru 29. Doug

PS, The white ground to that control box on that stud comes direct from the Ground wires AT the HWH pump mount bolts that hold the pump to the steel chassis mount plate. Verify the ground bolts are TIGHT on the 2 bolts on the pump mount.