Prodigy and third brake light problem

[Cryppie]

OK, just got my new car hauler, which I need to post pics of with my new graphics, and discovered a problem I can't find an answer to. When connected to my truck, with the Prodigy connected, the center brake light on the trailer (LED bar) flashes once every 4-5 seconds. I suspect that only the 3rd brake light does it because of the low amount of current required to make the LED's "fire". Tekonsha didn't have anything on their FAQ's regarding this, but I also suspect it is a continuity check run by the controller. Anybody else have this problem and more importantly (to me at least), a solution? BTW, the flashing stops when I disconnect the Prodigy, so I know that's the source...

 

[KBennett]

The Prodigy is probably sending a pulse to the brakes every 4-5 seconds to see if the trailer is connected.

You should probably contact them about the issue. It may have something to do with how the brakes are wired or you could add a resistor to the light to help bypass some of the current.

 

[Cryppie]

I received a reply from Tekonsha today, quick service I must say... he confirmed that the Prodigy does send a pulse every 4-5 seconds looking for resistance in the brakes for connection. Apparently trailer manufacturers go the cheap way (go figure) when adding a third brake light and tap into the electric brake wiring. Now I get to figure out where it connects so I can properly remove and rewire with a brake light modulator as recommended by Tekonsha. I'll post all the pieces and parts I need when complete for those that make have this issue in the future.

 

[KBennett]

All you will need is one wire. Find out where the brake lights are connected, disconnect them from the circuit and connect them to the brake light signal with a single wire.



Are all the brake lights wired to the brakes or just the 3rd light?

 

[Cryppie]

The problem is the brake lights come from the turn signal circuit(s). The left and right signals combine to make the brake lights. So, if I were to take just one of those, my 3rd brake light would also flash when that signal was used as well... I've been looking for a converter to go from the two wires to one feeding the 3rd light, but all I have been able to find is the other way; does anyone know if such an animal exists? It needs to accept the two turn signal inputs, but only output a single brake circuit. I'll keep looking, and also going back to my trailer manufacturer to see if they can fix it.

 

[Cryppie]

Solution found (I think)

Had some time to do a little research, and found this item that I think will work:

https://www.rvsurplussalvage.com/catalog/display.php?product_id=1600

I should have it sometime next week and work on installing then get a post up on how it works...



Fingers are crossed, now if I can keep my eyes from doing the same

 

[WestTN]

The trailer brake controller does not pulse the brake light circuit looking for a connection. It pulses the brake power lead. You would hear a tiny click in the electric brakes, but never see a light flicker. Since your LED third brake light is flickering you either have the controller brake feed tied into the brake lights or the third brake light is tied into the controller brake feed. You should have a left brake light, a separate right brake light and a separate electric brake feed as well as a taillight feed to the trailer. Make sure these are not crossed anywhere.

You should also have a good ground between the truck and trailer that goes through the plugs. Do not rely on the hitch ball for a groung. Loss of ground can do some surprising things with lighting systems.

 

[Cryppie]

Guess I was a little vague on my previous posts... the third brake light is tapped into the electric brake circuit, not the signals as it should be. I haven't traced the wire out yet to confirm this, but it does make perfect sense after reading the email from Tekonsha. I'll be disconnecting the wire from the electric brake circuit, and using the box I posted above with taps into the left and right taillights to get the feed for the third light. BTW, it's a 5er, and ground is solid.

 

[Cryppie]

Problem solved!

Well, the box I ordered didn't do the trick... it was exactly opposite of what I needed. Oh well, live and learn. But, it did hit me that what I needed was some sort of a "relay" that would only pass power when energized by two sources. So the more I thought about the "relay", I realized that all I needed was a... well, RELAY. Wired it up yesterday, and works like a champ. Pretty simple, and I'm still kicking myself for not figuring it out sooner. I used the left turn signal as the 12V source, the right turn signal for the solenoid, wired to ground and put my third brake light circuit to the output. It works like this: if the left signal is on, no power flows through the relay (solenoid has no power), if the right signal is on, no power flows because only the solenoid is closing, but no 12V to pass through the relay. It works well, and very simple. Hope those of you who have this same problem can use this solution!

 

[Jack Roderick]

Well, you're probably long gone by now, but just in case you're still around, in my opinion, you're a genius. I've had this problem since 2005 and got absolutely no help from the Prodigy Brake Controller manufacture. On several occasions, I contacted their support and got the same result, 'trailer not wired properly'. On the RV Forums, I got all kinds of suggestions. I knew the pulse was coming from the Brake Controller just couldn't come up with a solution that would work. Thanks for following through and posting your final fix. Jack