View Full Version : Tekonsha P3 Brake Controller / Focus FX17

05-13-2011, 09:40 PM
The setup (Tekonsha P3 Brake Controller) suggests starting at 6v and applying the brakes using the manual lever to see if the brakes lock or drag sufficiently. I have had it set at 11v and applied manually and the brakes do not lock. This seems strange. I would think the brakes would surely lock at that voltage level. This is all done at slow speed. Am I missing something or are the brakes perhaps not adjusted properly? The FX17 was just purchased. New!

Any ideas would be appreciated.


05-13-2011, 10:24 PM
Can you hear the brakes clicking at all? If not then it might be a connection/wiring issue. If you do hear them clicking on then they probably need to be adjusted. I have heard of brakes not being properly adjusted from the factory before.

05-14-2011, 07:36 AM
RichTully, I copied a few things from Lipperts web site that may be of some help. I don't know what brand of brakes you have but the principle should be the same.

Prior to any adjustments, your trailer brakes should be burnished-in by applying
the brakes 20-30 times with a 20 m.p.h. decrease in speed, e.g. 40 m.p.h. to 20 m.p.h.
Allow ample time for brakes to cool between application. This allows the brake shoes
and magnets to begin seating to the brake drum.

brakes should be adjusted after the first 200 miles of operation when the brake shoes
and drums have “seated.” Next, check and adjust brakes at 3,000 mile intervals or
sooner if they are not performing as intended.

I have also read that when you leave on a trip you should "warm up" your brakes. This involves applying some voltage to the brakes by using the manual lever on your controller. This will put a slight drag on the trailer. I use this method for about a block when we leave and it seems to help braking.

Just some food for thought.


05-14-2011, 06:10 PM
The brakes are coming on. I have them set to lead the truck brakes. It just seems that they are not contributing enough to over all stopping. Would hate to be on the highway and need to brake suddenly and find that they are not working well enough. I think I will check the brake adjustment when I get a chance. Not going anywhere for a couple weeks and so I have time.

Thanks for the replies.


05-14-2011, 07:51 PM
There is a troubleshooting feature on the P3. You can actually check controller output voltage and current. Iy may be putting out the required voltage, but if you have a bad magnet or a bad connection, you will not get full current, and hence not full braking. Each magnet draws 3 amps at 12 volts. So with the P3 set at max, you should see 12 volts and 12 amps on the P3. As a cross check, you can also check the resistance of the brake circuit at the trailer umbilical connector. You should see about 1 ohm between the brake line and ground.

05-19-2011, 08:24 PM
I will check out the current again though I seem to remember doing that before. Ordered a Trailer-Aid so will also check the brake adjustment when it arrives. Hopefully it will one day stop raining so I can get this done.


Rich Tully