Why Does My Boat Lift Go Up When I Press Down?

A boat lift that goes up when you press down almost always has a backwound cable. Someone kept lowering after the drum had paid out all its cable. The drum kept turning, the cable passed its anchor and started winding back on from the other side, and from then on every turn in the "down" direction pulls the cradle up. Lift Tech Marine's DC motor instructions put it in one line: if the lift runs the wrong way, "your lift was let down too far and now your lift is backwound."

The fix costs nothing: lower the cradle until the drum runs out of cable again, and it winds itself back on the right way. The other cause, reversed motor leads, has a different history: it appears on the first run after a motor, switch or remote receiver has been replaced. Neither fault is one to live with by pressing the opposite button, because the limit switches are now guarding the wrong direction.

Diagnose it by when it started

From the dock the two causes look identical: press DOWN, the cradle rises. What separates them is what happened just before, and which way the cable leaves the drum.

Boat lift running the wrong direction: symptom, cause and fix

What you see	Cause	Fix
Cradle went all the way down, then started back up with DOWN still held	The drum just ran out of cable and began backwinding	Let go. Press UP: the cradle drops back to its low point, then rises normally. Set a bottom stop
Wrong way at every height, after a deep lowering to launch, high water, or a lock-on switch left running	Backwound drum	Unwind it with the boat off, count dead wraps, inspect the cable
Wrong way at every height from the first run after a motor, switch or remote receiver swap; cable wound as before	Motor leads or control wires reversed	Power off. Electrician corrects the leads to the maker's diagram
Wrong only on the wireless remote; the key or drum switch is right	Receiver outputs connected to the wrong direction	Correct the receiver wiring; see remote control problems
One drum or one end goes the wrong way, the other goes right	That drum had fewer wraps and emptied first; or, with separate fore and aft motors, one motor's leads reversed after a swap	Boat off. Reset that cable to match the other, then relevel

Look at the drum

With the power off, look at where the cable comes off each drum: over the top, or from underneath. Drums of the same design on a correctly wound lift all leave the same way, toward their sheaves. A backwound drum leaves from the opposite side, and on a lift with two drums on one shaft the difference is plain side by side. Photographing the wind direction is one of the cable replacement steps, so check for an old photo.

A normally wound drum on a lift that still runs backwards points at the wiring. A wrong-way drum points at backwinding, whatever else was changed.

Lift Tech's rotation rule

Lift Tech Marine gives its direct-drive owners a check that needs no look at the cable: "When the lift is going 'up' the gear head should be going clockwise. When the lift is going 'down' the gear head should be going counterclockwise." A cradle rising while the gear head turns counterclockwise means the motor is obeying the button and the drum is backwound. A gear head turning counterclockwise when you press UP means the motor itself is reversed, which is wiring. Other makers publish their own rotation; Boat Lift Boss states for its drill backup, on the bottom of the motor shaft, that counterclockwise lifts and clockwise lowers.

Why the lift backwinds

A winch drum holds a fixed length of cable. At the lowest point the cradle should reach, the drum should still hold its dead wraps: at least 3 full turns, never fewer than 2, which carry the load by friction so the anchor clamp does not (see boat lift cables). Keep lowering and the dead wraps come off too. When the last one leaves, the cable hangs straight from its anchor, and the next turn wraps it on from the other side. The motor still turns the "down" way; the cradle now goes up.

That needs one condition: the drum must run out of cable before the cradle touches anything. If the cradle lands on the bottom first, extra lowering makes slack instead, which jumps grooves and overlaps wraps, a different fault covered in cable problems. Backwinding happens where the cradle hangs free: deep water, high water, a cradle lowered further than usual to float a boat off, or a cable cut too short at the last replacement. The usual ways it gets run that far:

• Holding the button. Boat Lift Boss's guide tells owners to go down only far enough for the boat to come off, because "running the system too long in the down cycle will wind the cable backwards and lift the boat."
• A lock-on switch. Lift drum switches come as maintained (lock on) or momentary (spring return); BH-USA sells its switch harness both ways. A maintained switch runs the motor until someone moves the handle back or a limit stops it, so an owner who sets it to down and walks away can backwind a lift with no bottom limit.
• A drill in an outage, or a hand wheel. Both reach the same end point, which is why lowering a boat lift without power says to stop when the boat floats.

How to unwind a backwound drum

Do this with the boat off the lift. If the boat is on a backwound lift now, UP is the button that lowers it: bring the boat down until it floats, take it off, then start here.

1. Clear the area. Nobody on the cradle or in the water near it. Stand where you can see both the drum and the cradle.
2. Confirm the drum is backwound. Check the wind direction as above. If the drum is wound normally, stop: this will not fix reversed wiring.
3. Lower the cradle with the button that now lowers it, which is UP. The wrong-way wraps come off as the cradle goes down.
4. Keep going through the bottom. When the last wrong-way wrap leaves, the cradle reaches its lowest possible point and pauses, hanging on the anchor clamp alone. That moment is why the boat must be off. Keep holding.
5. Let it rewind. The drum wraps the cable on the correct way and the cradle starts rising. In Lift Tech's words: "let the lift down, when it runs out of cable it will wind itself up correctly and start going up." UP is up again.
6. Find your real low point. Raise the cradle to the lowest position you actually need, with the bunks deep enough to float your boat at your usual water level. Power off.
7. Count the dead wraps on each drum at that point: at least 3, or your manual's number if higher. Fewer than 2 means the cable is too short for that depth and needs a longer one.
8. Check the wraps lie right, each beside the last in its groove, none crossing another. Fix overlaps before lifting the boat.
9. Inspect the cable at the anchor. The first few feet bent the other way under load. Kinks, flattening, broken wires or birdcaging there mean a new cable.
10. Set the stop. Set the bottom limit or auto-stop, if the lift has one, at the low point from step 6.
11. Test empty, then loaded. Confirm both limits stop the cradle, and that it rises level; a drum that backwound alone will be out of step with its twin (see lift raising unevenly).

The danger: the boat rises when you mean to lower it

Boat Lift Boss's guide says backwinding can "lift the boat, which could cause serious injury or damage." The worst moment is not the first backwind, near the bottom. It is later, when the boat is back up on the backwound lift, raised with the DOWN button, and someone presses DOWN again to launch.

The boat then climbs toward the top beam, and nothing may stop it. A top limit switch cuts the motor in the up direction. On a backwound lift the cradle rises while the motor runs in the down direction, so a limit that only interrupts the up circuit never acts. Reversed leads do the same: the motor runs down on the UP circuit and up on the DOWN circuit, so each limit sits on the wrong side. That is why the motor replacement procedure says to correct the reversing leads and never swap the control labels.

When a limit switch prevents it

A bottom limit switch set at the right point makes backwinding impossible from the button: it cuts the motor while the drum still holds its dead wraps. Three conditions apply:

• It must be set with the wraps on. A bottom limit set after a cable change, wherever the cradle happened to stop, may sit past the empty-drum point. Reset it at the counted low point.
• It only stops the circuit it is wired into. A drill on the motor shaft, a hand wheel, or a motor with reversed leads runs straight past it.
• It must be there. A top stop does nothing at the bottom. Check that your lift actually has a bottom limit or auto-stop before relying on it; without one, the person holding the button is the limit.

Reversed leads after a motor or switch swap

If the drum is wound the normal way but the lift ran backwards from the first press after a repair, the wiring sets the direction. A single-phase lift motor reverses when its start winding connections are swapped relative to the run winding; a DC motor reverses with the polarity of its leads. Two conductors connected the other way round between switch and motor flip it.

That is why lift switch harnesses carry more wires than a power cord. BH-USA's 110 V harness uses SJTW 14/5 cable (black, white, red, orange and green conductors), a drum switch for reversing lift motors up to 1 1/2 hp and 20 A, and an in-line GFCI, and ships with wiring directions for most brands of hoist motor. Direction depends on using the diagram for that motor, and an unlabeled or substitute motor is where it usually goes wrong (see replacing a boat lift motor).

This page gives no terminal connections: they differ by motor and switch, and the right source is the maker's diagram. Leave the box closed and have an electrician correct the leads. Dock circuits need the ground-fault protection in boat lift electrical. If the motor also hums, trips the breaker or runs one way only, start with motor troubleshooting.

Where this page stops applying

This covers cable winch lifts, whatever turns the drum: direct drive, belt, gear or hand wheel. Hydraulic and air-chamber lifts have no drum to backwind, so a wrong-way move there is in the valves or control wiring. A cable that has jumped a groove, crossed itself or left a sheave is a slack-cable fault, covered in cable problems.

Frequently asked questions

What does backwound mean on a boat lift?

The cable has been wound onto the winch drum the wrong way, because the lift was lowered past the point where the drum ran out of cable. The drum kept turning and wrapped the cable on from the other side, so the down button raises the cradle. Lift Tech Marine uses the word for a lift "let down too far."

How do I fix a backwound boat lift?

Take the boat off, then lower the cradle with whichever button now lowers it, usually UP. Keep holding as it reaches its lowest point; the drum runs out of cable, starts winding the right way, and the cradle rises. Then count at least 3 dead wraps at your low point and inspect the cable near the anchor.

Why does my boat lift go down when I press up after replacing the motor?

The motor's reversing leads, or the wires between switch and motor, are connected the other way round. If the cable is wound on the drum the same way as before the repair, it is wiring, not backwinding. Have an electrician correct the leads to the maker's diagram rather than relabeling the buttons.

Can I just use the buttons backwards?

No. On a backwound or reversed lift the top limit switch sits on the circuit you no longer use to raise the boat, so pressing DOWN at the top can drive the cradle into the beam with nothing to stop it. A backwound cable also passes over its anchor with no dead wraps every time the lift reaches bottom.

Sources and further reading

• Lift Tech Marine, DC motor instructions: operating the DC motor, gear head rotation, backwound lifts (https://www.boatliftanddock.com/MediaStorage/Product/Documents/Document/5113_20210707141151460.pdf)
• Extreme Max, Boat Lift Boss User Guide, 3311ex0519: lowering only far enough, backward winding, back-up drive rotation (https://images.homedepot-static.com/catalog/pdfImages/94/94be6af0-1237-4b8f-9f54-9cb5c4a53501.pdf)
• BH-USA, 110v Electric Motor Salzer Switch Wire Harness: switch rating, maintained and momentary options, SJTW 14/5 cable, in-line GFCI (https://www.bh-usa.com/?p=670256)
• Boat lift manufacturer owner's manuals: dead wrap requirements, wind direction and limit switch setting