front jacks on 5th wheel will not retract

[Larry-NC]

Originally Posted by 5picker

As Bama mentiioned, there are often times jumper wires on the back of the switch that can come loose and/or burn off. (especially if the crimp connections are poor)

Here's what the typical switch looks like.


Sometimes the switch has jumper bars built onto it.

Here's an internet snag of a schematic.
Wire colors may not be the same but the principal is.

That's a standard Double-Pole Double-Throw (DPDT) switch. When you wire it with the crossover wires, you can use it to swap the positive and negative connections to a load.

By happy coincidence, when you do this to a standard brush-type motor with DC, the motor runs in the opposite direction. Very easy way to make the jack go up or down.

(I've done this to the vent fans in our small trailer. Returning to it in the cool evening after a hot day, we just set one blowing in and one blowing out and flush the whole trailer in a few minutes)

The problem is switch selection. RV manufacturers do not do a good job of this. They use AC-rated switches on DC circuits and never seem to look at the current loads.

We just heard above that the jacks use a 50-amp fuse. I'll bet a six-pack the original and the O'Reilly replacement were 10 amp DC at best. I'll bet another one that you can't even find a 50-amp switch in the right physical size. Result: When you get that replacement switch, get two. You'll be needing the other one.

Motors and solenoids/contactors (devices with coiled wire) are a special problem in DC. They have a characteristic called "inductance"--once current starts flowing, it wants to keep flowing. When the switch opens, it arcs and burns the contacts. Too much of this and the inside of the switch is burnt up. Shake the dead switch and you can hear the burned pieces inside moving around.

Larry

[Photo Lab]

In all probability, the switch is the culprit, or possibly a wire off the switch at the top or bottom. The switch merely reverses the polarity of the 12 volts going to the motor to change direction. Quick (emergency)fix is to interchange the positive and negative wires going to the motor (typically red and black) Then operate the switch in the "extend" position, and the legs will retract, unless of course the fuse is indeed blown, which is unlikely, as I read the OP.

The switch usually has six terminals, and the motor connects to the middle pair.

[Blackrock]

Meanwhile as we wait for the results.

[onetonford]

Sorry I forgot but I also installed one of these. switch I bought was rated for 30amp but I liked the relay better and also installed a resettable breaker instead of fuse.

[Murbella7]

Don't forget that, like slideouts, you can hand-crank these things too. Be mindful of the shearpin (1/4 inch bolt. Don't be inclined to replace it with a hardened steel bolt that won't break like I did once) in the rod/bar the joins the two jacks to the motor, it breaks if you use too much force. Have a spare ready.

[doc73]

No help to the op... But I wonder if I can even hand crank mine. I'll add that to my list of check items.

[Larry-NC]

Originally Posted by Photo Lab

In all probability, the switch is the culprit, or possibly a wire off the switch at the top or bottom. The switch merely reverses the polarity of the 12 volts going to the motor to change direction. Quick (emergency)fix is to interchange the positive and negative wires going to the motor (typically red and black) Then operate the switch in the "extend" position, and the legs will retract, unless of course the fuse is indeed blown, which is unlikely, as I read the OP.

The switch usually has six terminals, and the motor connects to the middle pair.

Right, A DPDT switch has six terminals, and the two at each end are wired in an X.

As you stated, the power source wires can be connected to the center two terminals and the load can be connected to two terminals at either end.

However, you get the same effect if you connect the power source to terminals at one end and the load (motor) to the center terminals.

Fortunately, this means that if you swap the connections in the middle (with either style connection), the motor will spin in the opposite direction. Also, if you were to instead swap the connections at the end (with either style connection) the motor would also spin in the opposite direction. Isn't symmetry great?

Larry

[drelec]

I vote for switch

[DKe]

I had that problem with my 5th wheel & it ended up being the switch it would work one way but not the other replaced the switch & it worked great

[gdwash]

I had that problem on my 2010 29RLBS 5th wheel. My fuse was a 50 amp resetting fuse. It seemed that the up mode for the motor draws more amps than the down mode. My solution was to replace the 50 amp with a 100 amp fuse. The wiring is adequate for the load. The spike amps going up was about 65 amps which is enough to trip the fuse. It is very hard for you to catch that spike with a meter

[JohnD10]

Here is that inline fuse I was talking about earlier in this thread that likes to pop if you fully extend or retract and hold the switch a little too long: