What does STEADY test light on left turn signal mean?

[Miriam C.]

My philosophy is the more the merrier. I got frustrated and bonded the brake lights to the trailer and through the Tow.

[Dale M.]

I have always advocated using trailer frame as "ground"..... All the trailers I wire I bond ground wire to frame right at the "hitch".... IF trailer has electric brakes I bond the ground side of brake circuit at same "common" point... Even manufacturers assume one will be mounting "lamps" on some metallic portion of trailer infrastructure...

IF frame does not have integrity for ground circuit, it probably is to shaky to be supporting precious cargo.....

The concept of using frame as a ground is drilling hole in frame for ground connector, using screws and nuts or self tapping screws, using sand paper or grinding tool to get clean "bright" metal exposure, crimp a ring connector on wire end and protect all with dialectic (silicone) grease to prevent oxidation..... When it comes to tail light fixture that grounds through its mounting studs, I always clean surface the stud/nut contacts and apply dialectic grease.....

And just wrapping a wire around a screw IS NOT a proper connection.

If you think about it, mass of frame is capable or carrying more amperage than lamps will ever draw... Or any ground conductor can ever carry.

Dale

[BPFox]

The concept of using the frame as a "ground" is well established. That said, it must be noted that there really is no such thing as a "ground" in direct current circuits. What you are doing is using the frame as a conductor to complete the circuit from the load (light) to the negative terminal of the battery. The reason the frame is used is because it is easier and more convienant to use than any other method. The problem is it is also the number one problem area because it is easier to get bad connections. Paint and rust are your biggest problems and frames have plenty of both. This is especially true with bolt together frames. Getting a good connection is the key regardless of how you do it. Dale M brings up some very good points about making good connections. I prefer running the "white" negative wire the full lenght of the trailer. The negative part of the circuit is just as important as the positive side. You run full length un-cut wires all the way for the positive side so why not do the same with the negative side? I just got tired of chasing bad grounds. Once I run that white wire to all of the lights, the grounding problems pretty much go away forever. Not saying one way is better than the other, but it's more about the connections than it is about grounding the frame or not grounding the frame. My way just works without grinding any paint. In fact, my way works even if the frame is made of wood. Peace.

[brian_bp]

All valid points, Dale, except maybe this one:

... Even manufacturers assume one will be mounting "lamps" on some metallic portion of trailer infrastructure...

Lots of trailers have no lights using the frame for the negative connection. Virtually no travel trailer has any lights mounted on the frame (they're in the body), so they all need at least some wire to the frame, and I think it's pretty common to not use the frame at all. My 1979 Boler doesn't have any lighting connections to the frame.

It seems that commercial trucks use the same lamps for the truck and trailer, and they seem to normally have wired negative connections (not just mounting screws as connections).

Even a normal steel-bodied car - which normally does use the body as the negative side conductor - doesn't "ground" the light fixtures via the body mounting anymore; they have wires to well-planned "ground" points. By the way, those points are usually well-protected and dry, not hanging out underneath getting splashed.

If I'm going to run a negative wire anyway, I'll run it all the way to the connection to the towing umbillical cable, since the bit of wire I would save by using the frame doesn't make up for the hassle of bad connections to the frame.

[Hinermad]

Using the frame/chassis as ground can have a couple of advantages:

1) It's cheaper - less wire to run. (The frame has to be there whether you run electricity through it or not, so why not use it?)

2) If constructed properly, the frame has less electrical resistance than any reasonable size of wire you'd care to run for your ground.

All of the suggestions about cleaning, bonding, and proper attachment of screws comes under "constructed properly." Joints in metal frame members - especially bolted ones - can become a problem electrically because as they age they may get dirty, rusty, or just not put back together right after a repair.

I had a Ford Pinto once that was involved in a head-on collision. They replaced the front left quarter panel, but when they bolted on the new one they apparently didn't clean off the paint at the attachment points. The car's voltage regulator was mounted to the inside of the panel in the engine compartment and used it for the ground connection. I had two regulators fail before I realized it was a ground problem and ran a piece of copper braid from the regulator mount to the alternator mount on the engine itself.

Having a low resistance ground is a good idea for a couple of reasons: it carries more current (which means you're more likely to blow a fuse if something shorts, which is actually a good thing) and it also reduces crosstalk for low-level circuits like speakers or radio antennas.

Dave

[BrwBier]

If you just want to get by then by all means just ground to the frame. If you want to build in the best most trouble free way then run wires. No wire you are likely to use will be too small to keep a fuse from blowing. If the cost of a ground wire is whats keeping you from using it then skip one cup of coffee or a pack of smokes or walk one day instead of driving, each will save enough to buy the wire you need. This isnt ment to start a battle, I would not try and tell someone how to progran a computer or be an accountant or even paint a car because I dont do those things. I do repair cars and have done so for 30 years, if you bring your car where I work it will never be just to get by, it will be right.
Brwbier

[madjack]

...I think the term, PROPER BUILDING TECHNIQUES, applies here as much as anywhere...done properly, either method will work and screwed up, is screwed up, no matter which way you did it...PBT is what it's all about.....
madjack

[kayakrguy]

Hi folks,

Thanks for the good replies! Dale mentioned dialectic grease--where do you get it? Ive checked 3 places...no dice...one was an electrical store...

Jim

[Kevin A]

Hi folks,

Thanks for the good replies! Dale mentioned dialectic grease--where do you get it? Ive checked 3 places...no dice...one was an electrical store...

Jim

Any auto parts store that carries Permatex products should be able to get it. http://www.jamestowndistributors.com/us ... o?pid=8196

[Hinermad]

If you just want to get by then by all means just ground to the frame. If you want to build in the best most trouble free way then run wires.

In electronic designs where money is no object or where you can't afford a problem, they do both. The designer will pick a point on the chassis and call that "ground," (actually "common") then run ground wires from each module or assmbly to it.

For example, the grounding screw on the tongue could be the common point, then every light and connector would have a separate wire to it. That way you're not relying on the frame to carry current, but if a wire or light shorts out to it it'll blow the fuse so the trailer won't be "hot."

Dave

[BPFox]

"That way you're not relying on the frame to carry current, but if a wire or light shorts out to it it'll blow the fuse so the trailer won't be "hot."


Hate to break the news to you but if you ground your frame with the negative wire it is already hot. In direct current circuits both positive and negative are "Hot". Current is flowing in both the wire and the frame.

Here's a little experiment for you. Take a wire directly from the positive side of the battery and then touch the bare, grounded frame with it. What happens? Sparks fly right. Now tell me this. Did the spark go from the wire to the frame or did the spark go from the fram to the wire?

Now most folks will tell you the current travels from positive to negative, but there is pretty fair sized group in the electronic community that will tell you it flows the other way. In reality it does not matter. In a complete DC circuit, both the positive side and the negative side are hot.

[kayakrguy]

Hi guys,

Finally finished wiring today (3rd day of 95-100 degree heat--brutal.

I finally just replaced the whole harness--there were so many places that needed connectors I thought that would be asking for trouble up front where the wires move so much. Just got whole new wire/harness and reconnected everything, testing all the way. Hooked up car, did the 'grounded lightning bolt dance' to appease the 'lectric gods, turned on the lights and damn!, everything worked, so shorts, no burning wire smell, and the converter did not blow...at least not yet. Guy at Hecht says they are fine...(me...i thing, spring held push-in stranded wire in a trailer is bound to break....)
what the hell...am giving it a try...

Thanks again, everyone for all the help....

Jim

[Dale M.]

Good!......

Now lets end the thread........ Some things offered in this thread have been absolutely silly...

Dale

[kayakrguy]

Good!......

Now lets end the thread........ Some things offered in this thread have been absolutely silly...Dale

There ya go, lookin' in the mirror again! <g>

Jim

[Moe]

Just signed on to this forum so I could interject some information. A good web site to get hitch and towing infomation is: www.putnamhitch.com They are a long time manufacturer of hitch products and have a wealth of information in their catalog. The convertor issue is covered in the "download electrial section form 2008 catalog" located on the home page. It is PDF form. I thought they might have a wiring diagram online but couldn't find it. At my last job (now retired) I sold parts for truck bodies and such and we sold Putnam products. Nice people to work with. I'm sure a wiring diagram is in the printed catalog which you can order online. Lots of electrical products and most wiring harnesses will just plug in somewhere on the tow vehicle. In their download they tell you where to look for the plug, that applies only to the 4pin plugs. Additonal, most frame hitches just bolt on and they have instructions online. They also give you an estimated install time so if you have someone else do the work you can see if they are fudging the time.