OK...how does one eliminate the feedback issue...i.e. trailer battery feeding back into LC...anyway to rig up a relay? and where to do it?...could the relay be on the trailer side? i have an 2003
How to connect a trailer brake controller to a (late?) 100 series TLC (1 Viewer)
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sorry, I don't remember. Isn't there a ground wire already provided with the connector?
I must have described this in details someplace but I just put in a relay to interrupt the line to the trailer battery. I think I put it somewhere inside the US DS rear quarter panel. I think I used the power to the 12V outlet there -which is key actuated IIRC- to shut off the line or not. The point being that I did not want the power feedback into the truck with the engine off..
I forgot but I would think the connector in question does not involve the power to the trailer battery line. Why don't you just check the 7pin connector for voltage. The standard pin layout can be found online.
My LX is an 01 and did not have the connector for brake control wiring. When I was a kid I worked at an RV place and wired 2 trucks nearly every morning so this was work I was familiar with. I ran 2 pairs of arcticflex wire to the rear to convert the 4 pin simple trailer wiring to a 7 pin RV style. Arcticflex is overkill and a bit bulky but I had it and was feeling indulgent. This allows me a constant 12V as well as lets me ground everything at the front under the hood. The brake control is a Tekonsha Prodigy and my brake signal wire is tucked with difficulty next to a terminal and then glued in the brake light switch connector. I feel that was a bit of a hack style solution but it doesn't have much failure potential. Personally I like the old hydraulic brake control units. Kidding.
As the various threads indicate, the signal and brake light converters are not robust. Mine has been fine, but then the wiring is correct on all of my trailers. The later factory wiring with 12V power mistake is not surprising: If Toyota were not making mistakes like that they would have the work truck market all over the world. From what Loud LX writes it sounds like they did not actually tow a trailer to test it.
I did not wire back up lights in to my system. Apparently trailers with surge brakes benefit from this so I might consider it next time.
Using a regularly available RV plug from Bargman I got about a year out of it before connection issues in the plug caused issues. I replaced that with a high end molded unit made in small #s for trucking companies. It cost a bunch and I am not that impressed with it, but it hasn't failed. The spring on the cover has rusted.
All of my connections are done with heat shrink butt connectors and are crimped with a ratcheting terminal crimper. Solder is less of a good idea as it can throw a lot of heat into the wire. If you really know what you are doing, solder and heat shrink all day, but the modern shrinkable crimps are incredibly reliable.
The biggest problem with trailer wiring is corrosion and usually it is not the truck's fault. Every couple of years, use a battery charger with an ammeter to test the lights and electric brakes of any trailer you tow. Electric brake magnets pull 1.5 to 2 amps per wheel. So a tandem axle trailer with brakes on both axles should draw between 6 and 8 amps. Less than that and you have a broken wire, more and you have a rare broken magnet. Do not try this with fancy electric over hydraulic brakes. However, looking at what the tail lamps and marker lamps draw, as well as the brake/signal lamps and writing it down will give you a baseline to compare to year after year. Or you can just clean up every ground in the system each year.
As the various threads indicate, the signal and brake light converters are not robust. Mine has been fine, but then the wiring is correct on all of my trailers. The later factory wiring with 12V power mistake is not surprising: If Toyota were not making mistakes like that they would have the work truck market all over the world. From what Loud LX writes it sounds like they did not actually tow a trailer to test it.
I did not wire back up lights in to my system. Apparently trailers with surge brakes benefit from this so I might consider it next time.
Using a regularly available RV plug from Bargman I got about a year out of it before connection issues in the plug caused issues. I replaced that with a high end molded unit made in small #s for trucking companies. It cost a bunch and I am not that impressed with it, but it hasn't failed. The spring on the cover has rusted.
All of my connections are done with heat shrink butt connectors and are crimped with a ratcheting terminal crimper. Solder is less of a good idea as it can throw a lot of heat into the wire. If you really know what you are doing, solder and heat shrink all day, but the modern shrinkable crimps are incredibly reliable.
The biggest problem with trailer wiring is corrosion and usually it is not the truck's fault. Every couple of years, use a battery charger with an ammeter to test the lights and electric brakes of any trailer you tow. Electric brake magnets pull 1.5 to 2 amps per wheel. So a tandem axle trailer with brakes on both axles should draw between 6 and 8 amps. Less than that and you have a broken wire, more and you have a rare broken magnet. Do not try this with fancy electric over hydraulic brakes. However, looking at what the tail lamps and marker lamps draw, as well as the brake/signal lamps and writing it down will give you a baseline to compare to year after year. Or you can just clean up every ground in the system each year.
It does charge the trailer battery through the stock 7 pin connector.
Is there a TSB on this?
Additionally, which Tekonsha Prodigy is recommended? There appear to be several different sub-models.
I just reached my hand up under the dash and connected the prodigy to toyota harness. I didn't take anything apart. Once I knew where it was it was easy. No feekback on an 04 either.
I have been reading a bit about this topic. I am a bit confused so hopefully someone can help me sort things out.
I have this:
It is located behind my rear crossmember (bumper). If i were to tow a trailer with electric brakes, would i still need one of those teckonsha prodigy brake controllers even though i have a 7-pin plug that says one of the pins is for "electric brake"? This 7-pin plug came with the truck when i purchased it. 03 LX
I have this:
It is located behind my rear crossmember (bumper). If i were to tow a trailer with electric brakes, would i still need one of those teckonsha prodigy brake controllers even though i have a 7-pin plug that says one of the pins is for "electric brake"? This 7-pin plug came with the truck when i purchased it. 03 LX
rusty_tlc
Dain Bramaged Member
Is there a brake controller connected to the pin? The connectors follow a standard numbering convention that doesn't mean all the pins are connected. What do you plan to tow? Lighter loads really won't need a brake controller.
Sent via the ether from my candy bar running ginger bread
Sent via the ether from my candy bar running ginger bread
I don't know if there is a brake controller connected to the pin. How would i be able to find out? I don't plan on towing anything large... yet. (boat perhaps in the future) Right now, i'm actually more concerned with trying to figure out how to charge a battery in my tongue box of my m416 utilizing the 7 pin connector that i have.
You do need the controller...marking on the socket assumes you have a live circuit from the controller to the socket.
Steve
I'll add a controller once I hit half a ton or so. State says that trailer brakes are required for trailers weighing one ton or more. Without electric brakes you'll see significant wear on the LC brakes.
Steve
If you don't have a controller installed in the cab, get to the back of the connector and see if there's a wire attached to the connector brake terminal.
E-Trailer.com or Hoplite websites will give you wiring info, Tekonsha's (sp?) website should have a controller manual you can download. Be aware that trailer wiring colors may or may not match industry standards...both truck side and trailer side.
Voltmeter or 12V test lamp is a necessity.
Unloaded weight of an M416 is 1170lb. Check https://forum.ih8mud.com/trailer-tech/235679-tongue-weight-m416.html . With that much weight unloaded, if the trailer were mine electric brakes would be a given. OT there's a TON of info you can use on the trailer forum here...just gotta' dig it out.
As to charging the trailer's battery...
Make sure you have the 'battery' terminal on the truck side connected. Normally, you'd run a 10ga wire from the battery to a 30-40A circuit breaker or Maxi-Fuse, then to a battery isolator, and finally from the isolator to the trailer socket battery terminal. The isolator allows trailer battery to charge, but prevents the trailer draining the truck battery when stopped.
Start by seeing what's connected on the truck side, and verify your trailer socket is connected correctly before mating the 2.
hth
Steve
re_guderian
SILVER Star
Prepping for towing a 2-horse trailer with the '04. Was able to just reach up above the vent tube and install the Prodigy wiring plug wihtout disassembling anything. easy-peasy. It's the only white, empty connector in the general vicinity up there. Even enough room at the back of the ash tray to push the male connector and ground wire through. Using a ohmmeter, I grounded it to a screw above the OBD II port. So far, so good. Got the air bags in the rear springs, so should be good to go. Prodigy P3 in the ash tray. What's the consensus, just some foam to wedge it in for infrequent use?
re_guderian
SILVER Star
And the 100 pulled 2 horses up some pretty steep hills just fine. Air bags inflated to max really helped the rear end stability. No bobbing or sagging, even with 6 people in the car.
