You cant do much better than the P3 unless you want to buy a new truck to get the factory brake controllers.  Below is a post I made (I doubt it would come up in a recent search) when I upgraded to the P3 in May of 2007.  One of the troubleshooting features of the P3 I should have expounded on is the ability to display amps.  This will tell you if all your brakes are working.......11-12 amps on a tandem axle trailer and all is well.  Less or more amps and you need to take a look at your equipment.

Ebay has some really good prices on the P3.  Search Ebay for item #250390900968.  I cant get a hot link to work.

Been good weather and on vacation so I’ve got a couple hundred miles on the P3 now.  The P3 only took seconds to install in my truck as it uses the same wiring plug and mounting bracket (I used the metal one) as the Prodigy. As for braking performance I noticed no difference between the P3 and the Prodigy (use same volt/boost settings) ……which is to say it performed flawlessly.  I do like the way the buttons are set up on the front of the P3 much better.  The voltage setting can be adjusted with the truck on or off, unlike the Prodigy which would change if you set it with the truck off.  You do not have to hold the manual knob (another advantage in my book) to set the voltage, and holding the up or down adjustment key will speed scroll through the volts by tenths.  The LCD screen has some amusing features, it displays the volts like the Prodigy but it also has a bar graph, which shows how much of the max voltage setting is being applied to the brakes.  The boost settings are indicated by a truck and trailer icon, with four different trailer sizes indicating no boost, B1, B2, and B3…..my wife found that feature “cute”. Different screen colors are user selectable, blue matches my Sirius radio. The troubleshooting and warning screens are obviously more informative than on the Prodigy due to the LCD screen…hopefully I wont  need them anyway.   Bottom line, you get what you pay for. The P3 has more features so it costs more than the Prodigy.  If someone is considering upgrading TO a Prodigy, then I would say spend the few more bucks and get the P3.  If someone is thinking about upgrading FROM a Prodigy, then I hope my observations were helpful. Ebay is apparently the place to get one, I paid $112 + $10 shipping = $122 - $20 rebate = $102 – selling the Prodigy to a coworker for $75 = my “upgrade” costing $27.

http://www.hiddenhitch.com/fitguides/pdf/N39526.pdf

I think I'll be shopping for a new brake controller soon.  On a trip this weekend, I realized the brake controller did not seem to be engaging when I braked:  the indicator lights weren’t registering (it goes from green to yellow to red on the controller corresponding to the amount of brake pressure), stopped and check the brake lights and all the lights are functioning fine (brake lights function when I step on the brakes, turn signals function, running lights all work, etc).   I did get the trailer brakes to engage by using the manual control.   Is the controller bad?  If its that easy it would sure be nice to avoid taking the whole setup into the shop to have everything checked out.

Was searching treads and came across this discussion.  If I'm replacing the brake controller I'll probably go with the P3.  I have LED lights on my trailer, and in the last truck I had a Prodigy which I loved for functionality, but it made the rear brake light pulse.  Followed my own trailer one night and it was really annoying.  Guessing the P3 has been upgraded to prevent that with the prevalence of LED lights. 

What type of controller do you have?  Sounds like I would check the wire coming from the brake pedal for signal first.

The P3 uses the same "pulse" to check for the trailer, it will flash your light the same as the Prodigy did.  If that bothers you, you could replace your dual function ID bar with a multi function ID bar.  The multi function bar receives its brake signal from the brake light circuit, not the electric brakes themselves as is the case in your ID bar. 

Or you could take a look at the Valley Odyssey II brake controller.

Finally getting back to this.  Wiring all seems to be connected fine at the controller end.  I was doubtful that was the problem, as the brake lights function on the trailer when I step on the brake pedal, the brakes themselves just don't seem to be engaging.   I tried plugging into a different trailer and got the same result.

I have a Tekonsha Voyager.