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Brake Controller load testing?

huffaz
Explorer II
Explorer II

Purchased 5th wheel new several years ago and I believe I've never had much braking since.  At the time, I installed a new P3 controller in my truck.  Controller shows everything working normal.  Have tried increasing voltage, boost etc.  Pushing manual lever while moving has no notiable effect, can't feel any braking from trailer.  Have had multiple shops look at trailer and all say no problem.  Last shop adjusted trailer brakes, tested magnets, wiring etc.  Is it possible the P3 controller is faulty even though it's display shows everything working?

3 REPLIES 3

huffaz
Explorer II
Explorer II

It is obvious the brakes are not working as they should.  The question is why?  The trailer tests fine on its own at multiple shops.  Brakes were adjusted by multiple shops.  The trucks brake controller shows no issue, shows trailer connected etc.  When using the manual lever, it shows expected voltage and amps.  When driving slow and using the manual lever, no brake action is felt at all.  However, I do notice some difference if I test with the truck wiring disconnected from trailer when stopping.  So brakes are working to an extent, just very slight.  Question is if it is possible the P3 brake controller is not supplying enough volts/amps despite showing it is on its display.

The test is do the brakes work or not...voltage and readouts don't matter. Make the shop do a test ride with you when they say it's fine. If it doesn't stop,  it's broken regardless of what they say or what the readouts are.  

Tammy & Mike
Ford F250 V10
2021 Gray Wolf
Gemini Catamaran 34'
Full Time spliting time between boat and RV

valhalla360
Nomad III
Nomad III

First test...slowly pulling out of a site, use the manual override on max...you should feel a strong pull. On gravel, it may even lockup the trailer brakes. No pull, the brakes aren't working. There is no doubt involved. 

At higher speed when using the brake pedal, it my not be obvious...unless they aren't working, in which case, it will take forever to stop even if you are standing on the pedal. But even at higher speeds, if you use the manual override, you should feel the trailer pull when you activate it.

Next time, go in the truck with the mechanic and run those tests with both you and the mechanic in the cab and it should be obvious if they are working or not.

Tammy & Mike
Ford F250 V10
2021 Gray Wolf
Gemini Catamaran 34'
Full Time spliting time between boat and RV