Trailer light woes.............

[Mark Christianson]

I have a snowmobile trailer that the lights act goofy when I have it on my pick up.

When I have the trailer on my pickup, and turn on the lights, the trailer lights are VERY dim at best. If I hit the brakes, the lights on the trailer dim down to almost nothing. Basically off.

If I put the same trailer on our SUV, it lights up perfectly.

Here is what puzzles me.

My boat trailer works just fine behind my pickup AND the SUV.

Why is it that my snowmobile trailer lights work on the SUV and not on the pick up?

[Paul Waldowski]

BLB,

Had pretty much the same happen to me. For my situation it was rust on rust preventing a good ground. It drove me CRAZY for a couple of days. Hope it doesn't take you that long.

[Borch]

You've got a ground issue. Often you get a good ground off the ball hitch. If one is clean and the other has some rust that is the likely culpret.

[Gissert]

As the others stated, you have a ground problem. I am having trouble with my trailer right now too.

It'll also help if you get 4 wheel drive.

[Bulldoggr]

I just bought a used snowmobile trailer. I rewired the whole thing. if you have a tip/tilt style trailer; you might want to do what I call a back up ground. This is what I did. the white wire coming off your flat 4 prong plug is your ground. I took self tapping screws. I took one of those electric fittings the blue ones with an eye in it. and I crimped not only that white wire. But a jumper wire out of that same fitting as well. I took and ran jumper wire in the tongue of the trailer down to where the pivot point is at and crimped another eye on that end. I then self tapped drilled the piece to the frame.

back up by the hitch I also drilled tapped into the frame and screwed the crimped eye piece .

Sometimes the ground is not good whne the pivot point is rusty. This way you are grounded in two spots.

I hope this made sense, and helps.

[Mark Christianson]

Just for clarification........

My truck pulls other trailers just fine. And my SUV pulls the snowmobile trailer just fine, but it doesnt work on the truck.

Thats what puzzles me most. I know the trailer works on other vehicles, and I can pull other trailers on my truck just fine too(except this one snowmobile trailer).

PS - Dont make me push you down Gissert.

[metrojoe]

All things considered, it still sounds like a ground issue.

[Mark Christianson]

Cool.

Thanks nukeemandlukem or whatever that handle is.

I'll keep that idea in the cards.

[PerchJerker]

How well do the plug connectors match up between your truck and the trailer you're having trouble with. Worn, loose, too tight to fit like it should, etc? Dirty or corroded connectors? The "mechanic-in-a-can" approach would be to drench both connectors in WD40 and then try it again to see if it makes a difference.

Tried any other trailer lights on your truck lately? Maybe something happened to the ground connection on your truck since the last time you pulled your boat??

[ChuckN]

Quote:

---

It'll also help if you get 4 wheel drive.

---

I concur, that will solve your problem, bub. LOL

My sled trailer is weird like that too. The trailer has to have a lot of weight on the tongue for the lights to even work. It comes down to a ground issue. Somewhere, somehow everything needs to be right for the lights to work.

[Mark Christianson]

PJ

Connectors look and feel solid on both ends.

The trailer is basically new and the connector on the truck was replaced in the last year or so.

Used some "mechanic in a can" before I left yesterday.

This was a problem this past spring. I had it happen when hauling stuff to the farm and back during food plot season.

Well, it went back in the garage and I kinda forgot about it until I needed it last night again.

So to answer your question if I have checked the other trailers on the truck, its a moot point, cuz this is actually a lingering problem that now reared its ugly head again.

PS - I will push you down Chuck, I will.

[Gissert]

Is the ball corroded or rusty? How about where the receiver hitch plugs into the frame? If that is rusty, and you ground thru the ball/hitch, that can cause problems too.

[Mark Christianson]

I love trailers.

Well, the receiver has been on the truck since 1997, so chances are good the connection between the frame and the hitch itself has corrosion/rust as well as the actual receiver itself.

But why o' why do some trailers work without a hitch? (no pun intended)

Headed to the garage right now.

[Macgyver55]

There are some real simple tests you can do to check the grounds. These can be done in a matter of a couple minutes. First, hook up a test light from the ground (white)terminal of your pickup connector to the (brown) tail lite pin on the same plug. With lights on it should light. If it does, the truck portion of the ground is good.

Next, connect the plug to the trailer light connector. Turn them on, and connect a jumper to the trailer frame (behind the tilt point) and then to the pickup frame at a solid clean point. If the lights get brighter, the ground is bad. You can use the same method to track down and isolate where the problem is. If it works right at that point, then move the jumper in front of the tilt point to see if that is where it loses the ground.

My guess is that the main ground wire from the trailer harness is corroded or broken where it attaches to the trailer, causing the lights to ground "through the ball hitch". Its possible that it works on the SUV because the hitch is probably cleaner than the one on the pickup and has not yet lost is continuity. When working properly, lights on a trailer should work even if the trailer is not connected to the ball (when plugged in of course). If they don't, something is amiss.

[Jeremy airjer W]

Macgyver55, you nailed it.

I think I would find out where that white wire on the trailer side runs to. I would guess that it is either green from corrosion or completely rotted off. A self tapper, eyelet connector, di-electric grease and I think you'll be in good shape.

Speaking of di-electric grease. Don't be afraid to use this stuff. I put it on every connection and reapply as necessary. I've never had a ground rot, a green pigtail, or a rotted bulb socket. A couple bucks and an hour of time will save you a bunch in the long run!

[gspman]

What AirJer said. I had a corroded connector last year that I actually "sanded" with some rolled up sandpaper and then I liberally coated with di-electric grease. It worked like a charm.

[sparkyaber]

Also- use stainless steel with the dielectric grease- fight the corrosion anyway you can. Of all of the trailer wiring problems I have incountered, all but one was a ground issue. The one singled out was a mouse that shorted out the tail lights. Instead of using a self-tapping screw I actually drill out the metal, tap it to a 1/4-20 size and thread in a bolt. with grease of course. One last thing always use the right size terminal for the job. If you don't you are asking for problems in the future.

good luck