Trailer Wiring Questions

[R C Cola]

I tow a lot of differant units some small and large. On some when I turn on the Emergency flashers after a couple of minutes the fuse will blow for that circuit.

Two possibilities; Install LED's on the truck (not sure if this is a good idea)

or Install relay to take load off the truck circuit. Would I have to install 2 relays one for each side or is there a way to do it with one. I already have one relay for the park and run lights that supplies trailer as a seperate circuit.

Not sure where to make the connection to cover both sides, ??.

This board has saved me and others many dollars, THANKS, R C Oo.

 

[mysteryman]

All First Genners Need To Read This !

Install the relays !!!!!! You are playing with fire !!!! Many of these trucks were lost to cab fires because of trailer lights. . Be glad the fuse blew first.....



We used to have a kit we supplied to the fleets to address the problem... It was not sold to the public... There was a lesser kit that was sold to the public

but it was discontinued long ago.....



Another thing to check is the pink with red stripe wire that runs from the fuse box to the head light switch for burning or melted plastic covering ... Look closely at the crimped ends where the wire connects... . If there is any sign of discoloration or look like they have gotten hot replace the wire and the crimp ends ! This wire is the main power feed to your running and tail lights... .



I have been asked by a few to write an article for the magazine about this serious problem... . I may later do so when I have some extra time... ...

But for now let me say this..... and I can't say it strongly enough... .



DO NOT RUN ANY TRAILER WIRING STRAIGHT THREW THE VEHICLE'S WIRING HARNESS !!!!!!! YOU RUN THE RISK OF LOOSING THE WHOLE TRUCK DUE TO AN ELECTRICAL FIRE!!!!!!!



I recommend running a 12 gauge wire from the battery threw a 30 amp switch back to the trailer running lights. For brake and turn use relays pulling off of the battery as well ... . Put the relays in the rear of the truck...



If you are using "flame thrower" mega watt headlight bulbs put relays on them as well.....



This electrical problem does not happen in a day to most trucks... . It often takes years of slow cooking the wiring to flame up... . But when it does happen there will be nothing you can do to stop the fire before it takes the dash/cab out..... and in most cases you loose the whole truck.....



I hope all of you take heed to this... I want these trucks to live on...



Later this summer I may consider making up the kits if enough people are serious and show enough interest... I myself do not need any. I have the kits on my trucks already... .

I tow a lot of differant units some small and large. On some when I turn on the Emergency flashers after a couple of minutes the fuse will blow for that circuit.

Two possibilities; Install LED's on the truck (not sure if this is a good idea)

or Install relay to take load off the truck circuit. Would I have to install 2 relays one for each side or is there a way to do it with one. I already have one relay for the park and run lights that supplies trailer as a seperate circuit.

Not sure where to make the connection to cover both sides, ??.

This board has saved me and others many dollars, THANKS, R C Oo.

 

[ARhine]

A thread 6 months or so ago had a device that one of the main adapter harness mfgs made. It went in line on the trailer wiring and isolated the trucks wiring from the trailer.



Was around $50 or so.



Search found this one on ebay for less than that, at this price messing with making your own is hard to justify.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=7934403043&category=33653

 

[Philip]

I have used one of those converters. If you have power cross over between circuits on the trailer. It will blow the converter box. They will not handle backfeed. This problem could happen real easy. All it takes is a rock to hit the main wiring bundle and mash two wires together. Been there done that.



NAPA sells one that looks just like that one also.

 

[JTCHess]

Hey Mysteryman, sign me up for a kit. I haul a truck camper on my truck and looking into buying a 5th wheel. Haven't had any problems so far, but why take a chance.



thanks,

John

 

[R C Cola]

Wiring hook-up ??

That kit sounds great but not available now. Where would I tie in the connection to install relays so as to not cause any further wiring problems.

Tried search, do we have a drawing available that would show how to wire in these relays ? Part of my plan is to reduce the load going thru headlite switch,

especially since it is known to be weak. R C

 

[southpaw]

Mysteryman ,I would also be interested in possibly 2 or more if you decide to make them. I'll check on the more part and advise. Would these only cover the first gens only? KE.

 

[tugboatphil]

RC,



I just got a safety recall kit, that was for a 2nd Gen. It fit mine just fine. It includes a new switch, color coded wire extensions, plug end for the wires, shrink tubing for connections and a relay that runs the pink w/red & the black w/yellow wire. A couple of the colors changed, and I have them out in the truck. I'll post it tomorrow.



The kit # is CAJM8190 and cost $38 at the dealer. Now with everything that was in that kit, it was the lowest alternative. They had a switch alone that was $49, and a switch with the wire extensions and plug for $96. Now how that can be is beyond me.



The good thing about what I installed is that I now have a female plug for the switch, and I can drop the switch almost to the floorboard with the wire extensions.

 

[MMiller]

OK, OK, now I am lost. I read the post a while ago and was planning on spending something like $100 for a relay/isolator/convertor kit that was pretty plug and play, now Phillip says bad idea . I don't want my truck to burn up, I want to fix this right, Mysteryman, you say to put relays under the rear of the truck. Now here in the rust belt, thats going to cause me more problems, unless somebody has a different type of relay that is well protected. I know how to make a relay work, and can wire it, I just can't think of any relays that will be very sealed. What options do I have??



I've been towing trailers for years, never lost the headlight switch yet, and don't want to. I know if I don't do something, it will fail when I'm a long ways from home in the dark.



Michael

 

[Featherman]

Seriously

I am in the process of wiring my truck so have lights and brakes for my trailer. Well I was until I came across this post!!!!!!!!



I emailed the gentleman selling the kits on Ebay and he replied as follows:



I have 1993 Dodge Ram 350 4x4 dually that I am going to wire.

I've heard from some folks on the TDR that wiring directly into the system for a truck of this year can be hazardous.

Ron



Hey Ron,

Haven't heard of any trouble on the Rams electrical systems,mostly the chevy and Jeep vehicles with separate or amber turn signals.

Here are the Hoppy plug in kits I have,

Click here: eBay Motors: NEW86-94 DODGE RAM DAKOTA RAMCHARGER TRAILER HITCH WIRE (item 8042726330 end time Mar-07-06 09:05:55



If you have any other questions feel free to ask!





Bottom line is I'm still confused... ... ... ... ... Don't want to burn the truck either.

 

[R C Cola]

Recall Kit ?

Tugboat, the kit you mention containing a "switch" , Is that a headlite switch ?

If so, the two wires that hook to the relay, Are they for the Turn signals, or

Flashers, or ? This might be just the ticket for what I am trying to do. Was there a drawing for how to hook in the relay ? RC Oo.

 

[hotram03]

ok I dont know how to wire a relay and make it work, #12 red wire from battery to the #30 on relay connected with fusible link?, 87 & 87a is power to accessories recieveing the power form the relay, 85 is hot from switched source? 86 is grounded? not sure, someone help

 

[mysteryman]

The kit you got will work but it puts the relay BEFORE the tail light harness that runs from the cab to the rear lighting ..... If you have your trailer plug spliced in at the rear of the truck the current will still be traveling down threw the tail harness to the trailer..... The kit you have is only solving half of your problem... ... .

RC,



I just got a safety recall kit, that was for a 2nd Gen. It fit mine just fine. It includes a new switch, color coded wire extensions, plug end for the wires, shrink tubing for connections and a relay that runs the pink w/red & the black w/yellow wire. A couple of the colors changed, and I have them out in the truck. I'll post it tomorrow.



The kit # is CAJM8190 and cost $38 at the dealer. Now with everything that was in that kit, it was the lowest alternative. They had a switch alone that was $49, and a switch with the wire extensions and plug for $96. Now how that can be is beyond me.



The good thing about what I installed is that I now have a female plug for the switch, and I can drop the switch almost to the floorboard with the wire extensions.

 

[Featherman]

Leds

Hey Mysteryman:



Does the same caution or warning apply if the trailer has LED lights? They do draw less current.



Thanks

 

[Philip]

Michael



Those converter boxes work pretty good. Some are plug and play. Some require some wiring work. The NAPA brand I worked with will not take feed back from the trailer into the box. The way around that problem would be hit a radio shack and get some one way diodes and put them between the trailer and the box. One on each circuit. No feed back could get to the box then. Its just an extra step I don't like doing when working on someones equipment.



Anyone thinking of using a converter box. Check with the mfg and ask about feed back protection. Do not call eather. Use email. That way you have a paper copy if a feed back condition blows the box.

 

[MMiller]

Where does the feedback come from? A bad ground? I'm just trying to figure out where the power would be coming from the trailer.



I'll keep watching this thread.



Michael

 

[Philip]

The problem I had was the wiring harness got mashed. It had cut the left turn signal wire and the tail light wire. When it cut them the tail light had touched the left turn signal feed wire. It threw power back to the converter. "Poof" it took out the left turn in the converter box.



I had NAPA do a warrenty on the box. Which I shouldn't have. But anyway I replaced the box and 1 week later the driver did the same thing agin only this time it was the right side turn and markers. This time I did not warreny return the box. I pulled the box and threw it away. This was on a IHC single axle tractor. There was no reason to use a converter box anyway. It was setup with trailer circuits anyway. No need to lighten the load on a switch when it used relays anyway. LOL

 

[MMiller]

"I see" said the blind man as he picked up his hammer and saw... .



Thanks Philip.



Michael

 

[JLEONARD]

Well I'm still confused.

I will be wiring mine soon to pull a trailer... . maybe once or twice only.

Should I sweat this? (Maybe I should use hand signals? I still remember how to do that. No not digital imputicus )

Jay

 

[Philip]

Jay if yours is a standard D model without all the extra lights a dually has and the trailer doesn't have much of a pair of stop and tail combo lights. I wouldn't worry about it to much.