Ultima 2020 help!!

[Dieselrod]

I recently hooked up my trailer to my truck and to my suprise I threw the 40 amp trailer fuse. After blowing two more (at $2. 99 each) I got the meter out and went to checking. All seemed to be working fine with one exception, The terminal on my truck plug for the brakes is constantly reading 11 to 12 volts. Should this terminal always be hot? After unplugging my brake controller and replacing the fuse again all the trailer lights worked properly. The tech at Jordan said there should always be power there, but this just doesn't make sense to me. Any help or advise will be appreciated. I should mention this is on the factory 7 pole plug mounted on the drop hitch.

Thank You,



PS. I hooked my brothers truck up to the trailer later and his controller seemed to work fine.

 

[RMcCulloch]

While you had your brake controller unplugged, did you check the brake circuit at the trailer socket to see if it was hot then?



If so, you may have a crossover from the 12V circuit (center wire, IIRC).



You might also try turning the control down to its minimum before testing.

 

[Huntmastr1]

RM,



I am Epowells brother...



We did check the power at the plug with the brake box unplugged and there was no power to the brake circuit.



It would seem to me that if the brake circuit did have power to it with out actuation it would only engage the trailer brakes, not blow a 40A fuse?



What a delimma



My truck has a Tekonsha brake controller and the trailer works fine connected to my truck.



His truck is wired through the factory harness and worked fine up till and including parking the trailer the last time it was moved?



All is fine until the trailer is plugged in?



Keep the suggestions coming.



Thanks

 

[RustyJC]

Originally posted by epowell1

The terminal on my truck plug for the brakes is constantly reading 11 to 12 volts. Should this terminal always be hot? After unplugging my brake controller and replacing the fuse again all the trailer lights worked properly. The tech at Jordan said there should always be power there, but this just doesn't make sense to me.

When the trailer is plugged in, the Jordan (and most other controllers) will show a "Connected" light, right? How does the Jordan know the trailer is connected? Because it applies some voltage to the blue brake wire and looks for a current draw down that blue brake wire through the trailer brakes and back to ground. I've never needed to measure this voltage, but it would have to be very small to minimize current draw through the trailer braking system.



Is this the first time you've ever used the Jordan? If so, are you sure you wired the controller up by wire function and NOT by wire color? It sounds like the B+ wire in the controller wiring is tied to the trailer brake output wire - this could be due to an internally shorted controller or a wiring error.



Here is the wiring matchup between a Tekonsha controller and the 1996-1997 Dodge Ram brake controller harness for an illustration. The Jordan will differ (it doesn't use the stop light lead, and the wiring colors may be different - I don't have my wiring diagram handy), but my point is the same:



Function******Truck******Control



Brake*******Lt. Blue*******Blue

Power******Red/Tan*******Black

Stop light*****White********Red

Ground*******Black********White



Rusty

 

[Huntmastr1]

Rusty,



Again I am replying for EPowell.



The unit is wired correctly and has been operating correctly on several different trailers including the one that the problem was discovered.

I agree there would need to be a small current in order for the green continuity light to operate although I wouldn't expect it to be 11 + volts.

I will be checking my Tekonsha this evening to see what voltage it has to the brake power wire while controller is not activated.



Regarding the wire colors, you are correct in the fact that you cannot go by the wire colors. They change from year to year.



Thanks for your input and any future suggestions you may have.



Jeff

 

[RustyJC]

Well, if it was working fine before, and if the trailer works fine plugged up to another truck, I'd say it has to be either:



1. A defective controller or



2. A short in the truck wiring harness between the controller and the 7-pin connector.



Jeff, if you're willing to risk your controller, you could unplug it from your truck and plug it into your brother's truck. If it worked, you know the problem is in the controller and/or wiring pigtail. If it doesn't work (or if your controller possibly fries! ), you know you have a short in the harness or 7-pin connector. Otherwise, I'm afraid you'll just have to ring each wire out from the brake controller plug (check it for continuity, short to ground and short to any other conductor) to the 7-pin connector. Be sure to check the other wires coming into the 7-pin connector as well.



In addition, the factory 7-pin connectors aren't sealed worth a darn - they can do some funny things when they get packed full of water and grit - my Jordan showed that the trailer was connected with no trailer plugged into the 7-pin connector! If you've never done so, it's worth disassembling the 7-pin connector, cleaning it out with contact cleaner or WD-40, packing it with dielectric grease and putting it back together.



Rusty