If your winch spools out but won’t spool in, the fault sits on one side of the directional circuit: a bad solenoid on the “in” side, a broken wire or worn contact in the remote, or a loose cable between the control box and the motor. You can find it with a simple elimination test: reverse the remote leads, then the solenoid leads, and watch which direction the problem follows. Whatever the problem follows is your culprit.
Safety First
Winch circuits carry hundreds of amps, so treat every terminal with respect. Disconnect the positive battery lead before loosening or swapping any solenoid cable. Tape off disconnected cable ends so they cannot touch metal or each other, and keep tools clear of live posts. Reconnect power only when you are ready to test.
Confirm Exactly What Happens
Before you touch anything, run the remote in both directions and listen carefully. What you hear tells you where to look:
- Spools out normally, silent when you press “in”: the “in” signal never reaches the solenoid. Suspect the remote switch, its wiring, or the trigger wire to the solenoid box.
- Spools out normally, faint click or buzz on “in”: the solenoid is getting the signal but its contacts or connections are bad. Suspect loose solenoid cables or a failed solenoid.
- Spools out normally, “in” does nothing at all: could be either of the above. The tests below will separate them.
If the solenoid clicks in both directions but the motor never turns either way, you have a different problem. See our guide to a winch solenoid that clicks but won’t move for that fault.
Test 1: Rule Out the Remote
Remote switches fail on one side more often than people expect. One contact inside the switch handles “in” and another handles “out”, so a worn or broken contact can kill one direction while the other works fine.
A field-proven test, reported by owners who chased this exact fault: open the remote and reverse its two leads, so the “in” button now sends the “out” signal and vice versa. If the winch now spools in when you press “out” but refuses the other button, the remote is fine and the fault is downstream. If the failure stays on the same button, the remote or its cord is the problem.
While you are at it, check the plug where the remote meets the control box. Owners on the forums report missing or pushed-in pins and damaged plug sockets causing one-direction faults. Make sure every pin is straight, fully seated, and actually landing in a contact rather than plastic.
Test 2: Tighten and Clean the Solenoid Connections
This is the fix that ends a surprising number of one-direction faults. An old Warn M12000 owner described exactly your symptom, cable spooling out but refusing to spool back in with a faint click, and the cure was simply cleaning and tightening the connections inside the solenoid box. Terminals work loose over years of vibration and heat cycles.
With the battery positive lead disconnected, open the control box and check every large terminal: battery feeds, the leads to the motor, and the small trigger wires. Clean corrosion to bare metal with a wire brush, then tighten firmly. Do not stop at the terminals that look fine; the “in” side and the “out” side use different solenoids, so a loose connection on just one side produces exactly your symptom.
Test 3: Swap the Solenoid Leads (The Decisive Test)
If the remote checks out and the connections are clean, the solenoid itself is the prime suspect. On most winches, two solenoids (or two contactor poles) handle spooling in and two handle spooling out. One bad solenoid takes out one direction and leaves the other working.
Here is the definitive test, described by an owner who traced the same fault on an Engo 10000S:
- Disconnect the positive battery lead and tape the end.
- Label the leads running from the solenoid box to the winch motor, then reverse them (owners often mention the black and yellow leads, but wire colors vary, so go by your labels and the motor post markings).
- Reconnect the battery and try both directions on the remote.
If the winch now spools in but refuses to spool out, the fault moved with the swap and you have a bad solenoid on the original “in” side. If nothing changes, the solenoid box is likely fine and the fault is in the wiring or the motor.
When a solenoid is confirmed bad, replacement control boxes for many popular winches run around $50, which is why some owners simply swap the whole box rather than individual solenoids. If you do replace a single solenoid, owners report that the rest tend to age together, so replacing the set is reasonable insurance.
Test 4: Check the Motor
A motor can fail on one polarity too, usually from worn or seized brushes. The WARN direct-motor test settles it:
- Put the winch in freespool.
- Disconnect the positive battery lead (leave the ground attached).
- Label and disconnect the three cables from the control pack to the motor posts (marked A, F1, F2).
- Run a short jumper wire from post A to F1, then apply battery power to F2 with jumper cables. The motor should run in one direction.
- Move the jumper from A to F2 and apply power to F1. The motor should run in the opposite direction.
If the motor runs both directions on direct power, it is healthy and your fault is upstream in the solenoids or wiring. If it runs in only one direction or not at all, the motor needs a rebuild or replacement.
Quick Diagnosis Table
| Symptom | Most likely cause |
|---|---|
| Spools out, “in” is completely silent | Remote contact or broken wire on the “in” side, or its trigger wire |
| Spools out, faint click or buzz on “in” | Loose connection or failed solenoid on the “in” side |
| Problem flips direction after swapping solenoid leads | Bad solenoid, confirmed |
| Problem stays put after swapping leads and remote test | Wiring fault between control box and motor, or motor issue |
| Motor runs both directions on the direct battery test | Motor is good; fault is in solenoids or wiring |
| Motor runs only one direction on the direct test | Motor fault: worn or seized brushes, water damage |
When to Replace Instead of Repair
Repair almost always wins for this fault: a replacement solenoid or control box is inexpensive and the motor is usually fine. Consider a new winch instead when the motor fails the direct test on an older budget unit, since a new motor can cost nearly as much as the whole winch. If you go that route, see how to install a winch on a truck to get the wiring right from the start.
Frequently Asked Questions
Why does my winch spool out but not spool in?
One side of the directional circuit has failed: the solenoid that feeds the motor for the “in” direction, the remote’s “in” contact, or a loose wire between the control box and motor. Run the elimination tests above, swapping the remote leads first and then the solenoid leads, and the problem will point at the faulty part.
Can a bad remote cause the winch to work in only one direction?
Yes. The remote’s switch has separate contacts for “in” and “out”, and one can wear out or break while the other works. Reverse the remote’s leads as a test: if the fault follows the button, the remote or its cord needs repair or replacement.
How do I test a winch solenoid for one direction?
Disconnect battery power, label and reverse the leads from the solenoid box to the motor, then reconnect and test both directions. If the dead direction flips, the solenoid on the original side has failed. Replacement control boxes for many popular winches cost around $50.
Should I replace all the solenoids or just the bad one?
Replacing just the failed one fixes the fault, but many owners replace the whole set or the complete control box. Solenoids age together under the same heat and vibration, so the survivors often fail soon after. On sealed units you replace the whole box anyway.