How to provide 12 volt to gooseneck trailer winch and lift??

I have had this issue on several trailers. If you use the 12 volt pin in the trailer light plug to keep the batteries charged for an electric winch or a power lift tail, you can/will blow the fuse when using the winch or lift.

I have three large batteries on my trailer. One provides the power to the hydraulic dove tail. The other two power the electric winch. Using the light plug/wiring to keep the batteries charged works fine. The issue is if I leave the trailer light cord plugged into the truck when I use the hydraulic lift or the electric winch, it will blow the fuse as the small charge wire/circuit tries to carry the load. I tried a circuit breaker and it gets the wiring hot.

I have had this issue on the last three trailers I have had an electric winch on.

Is there a way to keep the batteries charged and not have to unhook the light plug when I sue the winch or lift???

I am not going to run heavy battery cable to the trailer from the truck batteries.

Toggle switch or house switch close to the winch cable?

You could add a relay in the winch control circuit to disconnect the charge line when the winch is switched on.

A simple way is to put a single pole single throw switch at the control for the winch. Connect it in the wire from the vehicle. Switch off to run the winch, switch on to charge. A normally closed relay could be put in this same place and its activation coil could be hooked to the power going to the wench motor. As soon as the wench is activated, the relay opens the wire to the vehicle. Jim

1. If the trailer battery(s) are in good shape and charged up, it would surprise me to see this happen.


2. Shut off the truck. In many/most cases when the ignition switch is "OFF" on a modern vehicle, a relay opens, cutting power to the "hot" wire in the trailer connector. (Or maybe NOT???)

Didn't you used to be able to buy an "isolator"? which allowed charging to batts then blocked it from drawing on the truck. Just wondering

i have a winch on my trailer, the battery is just above the gooseneck hitch (marine deep cycle) and have a solor panel 5 watt hooked to it to keep it charged. only use it randomlly, always works

JD:

Put a "Blocking Diode" (one-way gate) on the Charging line just before it connects to the Batteries. The Diode will allow the truck to charge the Batteries, but stop the current from back-feeding the line.

Doc

Yes, that's what I would do. The only think I would suggest different from Jim is to use a SPDT relay, tying one throw to the charging line and the other to the winch. That way the winch can't draw any current until the power lead is disconnected.

I use a marine deep cycle on my winches on two goose necks with no problems.

I didn't have batteries on my trailer when I had a hydraulic pump to lower or raise my heavy dove tail. I used one large lead and installed a plug on the front of my trailer and one on the truck. The ground was supplied thru the frames. I fused it with a 100 amp fuse. Never had any trouble. Most always what we don't want to do is what we have to do. Just my experience.

Sounds like the hydraulic unit is using a lot of power.I have a 30ft trailer with a 10ft hydraulic dove tail that uses one 12 volt battery,but I have cables from my two truck batteries to the trailer battery for extra boost.The trailer is 15 years old and never had a problem with power.

Adding a isolation relay is a good way to do it. Just get a low-draw continuous-duty relay that connects your front batteries (under the hood) to the trailer's. My truck is wired with #2 copper cable from the truck to the trailer with 100 amp breakers on both ends. Besides protecting the front batteries, it allows a lot of charge current to get to the trailer to recharge the batteries.

Simple fix is to put a switch in the wire (on the trailer) that supplies power from the truck to the battery to keep them charged. Bandit

Just some additional information. This trailer is used on 3-4 trucks. So I want whatever is needed to be on the trailer.

Also all the batteries are deep cycle marine batteries. They all are in good shape.

The trailer does have a solar charger. It works OK if the trailer is not used very often but if you use the trailer regularly it does not keep the batteries charged. The wire from the truck is needed. The reason I know this is one truck's charge wire was not working and the batteries would go low after raising or lowering the dove tail several times.

I also thought about a diode. Will that work??? The reason I think it will not is that the current is always going toward the trailer anyway. The diode would stop a back feed but not an "over" feed.

I need to limit the current draw to about 30 amps. That would easily charge the batteries but would not blow the fuses in the trucks.

The Ford F350 is the worse. It has two sets of fuses. One for the truck and another for the trailer plug. Some times the trailer charge circuit will blow the fuse in the trailer box and a feed fuse in the main box. The main box is stuck under the washer fluid pump and is a pain to change.

I am thinking about a relay that is close when it has no power on it. This would allow the batteries to charge. Then run a wire from both the winch and hydraulic pump that would energize the relay whenever either was used.

It should be a simple thing but It has me stumped. LOL The issue is whenever the trailer battery voltage goes below the truck batteries then the charge wire tries to carry enough current to run the functions.

If the trailer was used on ONE truck I would just run a heavy wire separate wire to keep the trailer batteries charges at all times.

on mine I used a set of old cables from a drill fill auger, I still have a battery on the trailer as well but found this way if it is weak or you need extra power this works great! I just run it to the truck battery and clip them on, no blown fuses hot wiring ect, and it works on any truck, I just bolt the eye in the cable to the battery post and then when done takes just seconds to remove and roll up for storage in my box on the trailer
cnt

I worried about the problem you're having when I put the winch on my trailer but have never had any problem. 12k winch with deep cycle battery behind a F250 using the factory wiring. Can bring the winch to it's knees and not blow a fuse. You're right, a diode will not do what you need. The relay idea should work and you would not have to remember to change anything every time you use the winch. With a manual switch, you'll forget when you're in a hurry one day.

OK...you say you don't want to run "heavy battery cable to the trailer from the truck batteries."

Congratulations; you just ruled out the most logical way to solve the problem. Go ahead, continue to be stubborn, and continue to have the same problem until you die; it ain't MY truck, it ain't MY trailer, and it don't matter to me if you fix the damn thing right or not.

BUT...if you ever decide to come to your senses, here's an idea: ever see those quick-connectors for jumper cables that those old-time wreckers used to have? Yeah, the one-ton Chevys and Fords with the little Holmes 440 sling-style wreckers that were everywhere before the industry switched to wheel lifts.

You can buy those connectors...believe it or not. And they'll handle all the amps you want for your winch or your power tail lift, and NOT blow the fuses if they're connected [and protected] properly. Using this setup means you don't HAVE to run all those amps through your standard trailer connector and have all kinds of mean, nasty, ugly things to deal with that direction.

Or, you can keep your head buried in the sand and keep using half-fast "solutions" that leave you dissatisfied. No skin off me whether you decide to do it right or not; I just don't want to be responsible for you saying later, "Hey, nobody ever mentioned THAT solution before."
Bet even YOU can find these

...plus, if the need ever arises, you can even use the connector to jump-start your truck(s) from behind. That's handy if one ever dies on a lot where vehicles are parked nose-to-nose and you simply can't get closer without pushing the truck out of the parking spot.

JD - I scanned your message real quick, so I probably missed something. On the relay idea - the little 30 amp "ice cube" relays could be wired downstream from your truck (on the trailer) to open and isolate the charge line when you applied power to either of the accessories on the trailer. Off hand, you may need two of them to prevent backfeed between the accessories - I don't have the pinout handy for them. They are CHEAP. Throw a couple spares in the glovebox. I use them for everything where I'm looking for isolation, and it's rare to have one fail. Would work behind any vehicle. The heavy cables would be ideal, but for multiple vehicles, not so good on the pocketbook.

Use the last one on the bottom of the list. Wire it in between your truck wire and battery and you'll have no over charging or amp draw problems. It will take a while to recharge the battery after a lot of use tho, so if you do a short trip with heavy use it won't keep up.
Untitled URL Link

As others have said, a normally closed relay from the truck before the batteries on the trailer would just shut off the juice from the truck while power is being used. If you want to get by with just one relay then have diodes in between the relay activating wire and the switch running the load. Without that, activating either switch would run both loads.

JD, Electrical and Legal questions get the most responses from about any topic on here, I enjoy them and try to help when I can, so FWIW heres my take, which is worth what you paid for it ZERO lol

Even if its NOT how I may do it, I'm basing my answer on YOUR requirements:

"Is there a way to keep the batteries charged and not have to unhook the light plug when I sue the winch or lift???"

MY RESPONSE YES by using a toggle switch or an isolation relay, see below

"I am not going to run heavy battery cable to the trailer from the truck batteries."

MY RESPONSE If you ONLY want the truck to charge the trailer batteries while driving (say 20 to 30 amps max) and NOT rely on high current or the truck battery to assist or be in parallel with the trailer batteries, a 20 to 30 amp circuit and NOT 50 to 100 amp circuits and breakers etc will suffice


1) The FIRST thing I would do is (if not already) upgrade the charge wire circuit on all your trucks FOR 30 AMP CHARGING CAPACITY to the trailer batteries. I would use a 30 amp circuit breaker at the truck battery and run 10 Gauge wire back to the trailer plug. (HOWEVER, if an isolation relay is used as described below in Para 3, the charging circuit runs from the truck battery to and through the relay and then back to the trailer plug.) NOTE If you don't want to upgrade and only have say 20 amp rated wiring back to the plug, then use an appropriate rated breaker such as a 20 amp etc.


2) In order that heavy trailer loads don't trip that 30 amp charging circuit breaker above, you could use a 30 amp rated SPST On/Off (Open/Close) toggle switch in the circuit from the truck to the trailer batteries and simply turn it OFF when you're going to operate the trailer. That prevents the 30 amp relay in the charging circuit from tripping.


3) Another method to accomplish the above WITHOUT having to remember to throw the switch, is similar to how my RV is wired with an isolation relay between my engine and RV house Batteries (yours would be to isolate truck from trailer batteries when truck isn't running). You only need a continuous duty 30 amp minimum rated 12 VDC coil NORMALLY OPEN isolation relay. Its wired with its 12 VDC activation feed to the relays coil from a truck circuit that is hot ONLY when the truck is on/running. That way when the truck is started the relay closes so the trucks alternator and battery circuit can charge the trailer batteries, but when the truck is turned off the isolation relay opens so the truck and trailer batteries aren't tied together and no relays will trip open.

My RV isolation relay looks like an old Ford type starter relay except its 100% duty rated (you cant use a normal starter relay, theyre NOT rated for continuous duty) and is at least 100 amp capacity. They are a fairly cheap and easy way to isolate truck from trailer or house batteries and are simply wired so they are normally open when truck isn't running but closed when it is so the charging circuit can charge the trailer batteries. A switch is easier and cheaper and all you have to do is turn it off when using the trailer.

YOUR MONEY YOUR CHOICE even if I prefer the slightly more expensive isolation relay so you never have to worry about it or to tell Billy Bob or Bubba to turn it off (and then back on) when using the trailer!!!!!!!!

Let us know

John T

The issue is that the flow is from the truck battery to the trailer in both cases. A diode won,t work like that. Jim

I have the same problem. I simply remove the fuse when using the lift or winch. I put a 20 amp circuit breaker on the tractor's charging wire, so if I forget, the circuit breaker will do it's thing. When it cools off it reset itself. The circuit breaker plugs in to the fuse holder, one that uses the larger flat fuse.

After I'm done with dump trailer, I use a charger to bring batteries all the way up. One time my sears 15 amp smart charger failed to shut off and one of the batteries produced hydrogen sulfide gas. So in the future I only charge with a batteryminder 12248. It does a better job, no more smell, I can charge both batteries at the same time with charger.

So try using a auto reset circuit breaker you can get at an auto store.

I keep the cables with the trailer, works for any pulling unit that way

Similar ideas, but he wants to use various pulling vehicles, So my normally closed Idea below addresses that, bu putting it on the trailer, and triggering it to open when power goes to the winch motor, or other device. Depending on how they are now wired, it might take a diode or two to make it automatic. Jim

You're right Jim, if he modifies the trailer he wouldn't have to rig each truck my way. In that case Id still upgrade any of the trucks charging circuits to 30 amps as in my first paragraph. Its fun spending other peoples money isn't it lol

John T

Buzzman72: There are several reason I do not want to use the truck batteries to supply the trailer.

1)A big one is the danger of running the batteries too low and not being able to restart your truck after you use the winch or dove tail too much.

2) Another is the danger of having 40 feet of battery cable ran back through the truck frame and trailer frame. It is hard enough to keep smaller wires form corroding with the liquid deicer they use on the roads anymore. Let alone one hooked up to high amps DC current.

3) The cost of wiring 3-4 trucks that use the trailer.

I do not see how having the batteries a few feet from the unit that needs them as being a half A$$ed way to do it. Your wanting to have the battery current run through LONG cables with CONNECTIONS that will corrode. That will mean that the voltage drop will be much larger than having the power supply right at the units.

I have had winches hooked up with the connectors you listed. The winch did not work very well because of the voltage drop from the truck battery. It was a constant battle to keep the plug connections clean enough to work.

I don't use my trailer that much and it sits inside. I have a 12K winch and hyd dovetail but I also have a solar charger. I have never had to charge the batteries and it is pulled by a F250.

I have a deep cycle battery on my trailer running my winch and I haven't had that problem. I started off by unplugging my trailer harness when I ran the winch, but I no longer even do that. I don't run the winch long enough to run the battery down, and I probably would have problems if I did. I would just put a switch in circuit to avoid it if I had problems.
If you choose to run big cables or jumper cables from your truck battery back to the winch, UNPLUG your trailer connector when in use. If for some reason the ground cable gets loose, all 300 amps are going to try to ground back through the trailer connector and its ground wire and it will melt your trucks wiring harness from the battery to the rear bumper. You can just imagine what that costs to replace.

All you need is two 25 ft pieces of welding cable to reach from your truck battery to the ftont of the trailer to the winch and trailer controls.I use welding clamp ends on the truck end and twist connectors on the trailer end.No need to run any cables through the truck or trailer frame.My 30 footer also has a 12 volt battery,but the factory told me I didn't really need it with two batteries in my duramax truck.
My bumper pull trailer uses the same thing.The voltage is actually higher from my truck batteries
through the cable than a battery at the winch or tail control.I've hauled tractors for 40 years with trailers and this has always worked.It's better to have two fresh batteries from the truck to use than a maybe charged battery on the trailer.It takes a long time to charge a battery through that little charge wire in the connector.It might be ok if you use your trailer enough to keep it charged up.I always carry one of those battery booster packs from napa in case a tractor won't start or if I'm to lazy to connect the cables to my truck battery.I just hook the booster to my winch and tail controls and it works fine that way also.

I'm surprised no one has mentioned how semis power trailer liftgate batteries,and,that your trailer is built without . I read below that you don't want to wire all your trucks that pull these trailers, and don't want to use battery cable.But,you are overloading your circuit:that is why you blow fuses.At the very least,if your batteries stay charged enough to run your winch and dove tail, you need to disconnect the plug while using them.A 30 amp breaker is not enough and your wiring is not heavy enough, if it is 14ga.
On semis,there is a separate power cord direct from the batteries,either double pole or single pole,with single pole grounding thru trailer hitch.(Double pole is better!)This system uses a 150 amp breaker and 4 guage cable. Then on the trailer is another 150a breaker at the batteries. Yes,there are corrosion problems, but there is a spray product to spray on all terminals called Glyptol, expensive, but it works. Battery cables and connections are maintenance items:they must be checked when you pm a vehicle.You already have to keep up with the motor and solenoid terminals anyway.
This system works very well,as it is the industry standard.I kinda doubt the small guage wiring of your factory plug would adequatley ever recharge your batteries without frying sooner or later,unless you barely use your winch or dove tail, and it seems the winch could get used for several minutes at a time,which would be a big amperage draw.Good luck,whatever you decide;let us know.Mark