Why is there Issues with My Relay when Operating My Plow After Installed the Superwinch Upgrade Kit?  

Question:

Expert Reply:

Hello Tim,

The Superwinch # SW2320200 upgrade kit is not mainly a heavier wire upgrade. Its purpose is to improve how the winch is electrically controlled under high load. The kit includes a sealed handlebar rocker switch, a wiring harness, and a high amp relay or solenoid control box that handles the large current needed to power the winch motor.

When you press IN or OUT, the switch sends a low current signal to the relay box, which then delivers full battery power to the motor in the correct direction. This keeps heavy electrical load off the switch, reducing heat and wear in the control circuit.

The main advantage of this kit is a stronger, dedicated relay system rather than larger battery cables. The wiring size stays similar, but the relay or solenoid pack is built to handle higher current more reliably than basic relay setups.

Relay failure is common when a winch is used to lift a plow. Plowing creates high current draw, repeated short cycles, and constant exposure to moisture and salt. Any weak battery or corroded connection increases heat in the relay contacts and leads to failure.

The upgrade kit helps, but good installation is still critical. Mounting the relay box high and dry, sealing connections, and maintaining strong power and ground connections are just as important for long term reliability.

Do you use the plow for personal use, or to make a couple of extra dollars as well? Where are you located? We are in Missouri, we got quite a bit of snow December 1st, but then 70 degrees on Christmas.

expert reply by: Kate F

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Tim B.

1/6/2026

kate this info has been very helpful.i have the rocker switch and relay box now . the relays seem to go bad often. they where installed under seat in sealed area also. I think I will get a new one just to be safe. I only use it for personal use. Im in long Island N.Y. Not to much snow but we do get hit hard once in a while. The relays number is sldh-12vdc-1c made by songle .I believe you have them made by bulldog. are they better I ordered 2 last week. These relays are difficult to find locally.please keep me posted with any advice.much appreciated.Thanks Tim

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Kate F.

1/6/2026

@TimB Thanks for following up Tim, glad the information was helpful. Even with the rocker switch and relay box installed in a sealed area, relay failure can still happen on plow setups because of the high load and repeated short-cycle use that lifting a plow creates. That kind of use is harder on relays than typical ATV or utility winch applications. The Bulldog Winch Replacement Relay - 60/80A - 14V DC, 5-prong plug - 2K/3K Powersports Winches # BDW20101 relays you’re using are common in these systems, but they are more of a general-duty relay. The Bulldog relays we carry are built for trailer and winch applications and are typically more robust in terms of contact material and consistency, which can help with longevity. That said, no plug-in relay is immune when used for plowing, especially during heavy or wet snow events like you can get on Long Island. If you’re already replacing the relays, having a spare on hand is a good idea. Beyond that, the biggest things that help extend relay life are making sure the battery is strong, all power and ground connections are clean and tight, and that the relay box stays dry and well-ventilated. Even a small amount of voltage drop can increase heat at the relay contacts and shorten their lifespan. I’ll definitely keep you posted if there are any better long-term solutions or updates that would improve reliability for your setup. Thanks for reaching out, and please don’t hesitate to reach out if you run into any other issues.

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Tim B.

1/7/2026

thanks Kate you where very helpful. I ordered the bulldog relays. I think I will order new kit and change it out.mine is about 12 years old so it would be smart to change right after winter. also is there a part number for a new rope for plow. that looks little worn also. talk soon

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Kate F.

1/8/2026

@TimB Thanks for the kind words Tim. Ya, probably not a bad idea to swap it out at the end of the season. The Superwinch LT2000 winch originally uses a 50-foot wire rope with a 5/32-inch diameter. That exact size is no longer available, but the closest and best replacement I can currently offer is part # FWC7500100. It is 50 feet long with a slightly larger 7/32-inch diameter, and it will work well as a replacement for your setup.

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