My 90 F250 already had a brake controller installed when I bought it, but I've never towed anything with it yet. Just got a race car and trailer now and would like to test it out (my dad towed it up, so it still hasn't been hooked up to my truck).

Testing the lights is pretty straight forward but is there a way to test the brake controller other than just hooking up and going for a drive?

 

On the controller itself, there should be a slider mechanism that you can slide with your hand. That applies the trailer brakes independent of the truck. In a suitable location, put your truck in drive, slide the thing on the controller, and take your foot off the brake. The trailer brakes should hold you back. If not, adjust the gain (a dial or buttons) up until you get some resistance from the trailer brakes. If nothing still, either the trailer brakes are out of adjustment or you are not getting power to the plug at the back of the truck. That should be part of a pre-trip inspection EVERY TIME the trailer hits the road.

 

Yes, if you want to invest some serious bucks (I think it is about $200 now), you can get a tester that plugs in and mimics the trailer brakes. When you activate the controller manually, the tester has a screen that reads the number of amps the controller is sending to the brakes. Otherwise, you can get much cheaper versions that plug in and will light up when the controller is sending current to the seven pin plug, but it will not give you an amp reading, which is what you really want.

Now doing that will tell you the controller is sending power to the plug, but it will not tell you how your truck and trailer work together and that is the crucial factor in trailer braking. That means you have to be hitched and moving to make sure everything is working.

Steve

 

My initial test when hooking up a new system is to get it all wired, then jack up the trailer axle to get the wheel off the ground, spin the tire and apply the brakes to see if they work. Repeat for each braked wheel.
Then I go for a gentle drive to see if they work on the road and adjust the controller if needed.

 

That certainly works. I am just way to lazy to jack up the wheel to test!

Steve

 

You can usually verify that the controller is communicating with the trailer by having one person press on the brake pedal while the other listen for the "hum" at each wheel.

Starting off very slow and applying the brake manually will help with the bias. To the other's point, always good to test in a safe area. When stopping, you should get a smooth feel when almost stopped. If it jerks, too much bias.

Most aftermarket controllers have essentially a coarse and fine adjustment and you will need to get both right.
You will have to play with it a bit to feel comfortable.

In this case, too much is just as bad as not enough IMHO.

 

Not sure I would say just as bad, but certainly not good. If it's enough too much you'll skid your trailer tires which will make them out of round and can quickly wear them to the cord.
Don't ask me how I know, but I'll plead youth

Actually it was also the brake set up on my dad's 77 F-150 with hydraulic actuated brake controller. Even dialed to the lowest setting it would skid the tires when the trailer was empty.
The addition of an external rheostat solved the problem.

 

Man, the only plea I can ever make is stupidity, but I have done plenty of that!

Steve

 

Well, unfortunately, I'm way past ever being able to plead youth anymore.

 

A lot of good information has been posted above - copied and posted below is from the FORD owner's manual on how to adjust - test the trailer brake controller

As with all of my posts take and use what you find useful - disregard the rest


Procedure for adjusting GAIN:

The GAIN setting is used to set the TBC for the specific towing condition
and should be changed as towing conditions change. Changes to towing
conditions include trailer load, vehicle load, road conditions and weather.

The GAIN should be set to provide the maximum trailer braking
assistance while ensuring the trailer wheels do not lock when braking;
locked trailer wheels may lead to trailer instability.

Note: This should only be performed in a traffic-free environment at
speeds of approximately 20–25 mph (30–40 km/h).

1. Make sure the trailer brakes are in good working condition, functioning
normally and properly adjusted. See your trailer dealer if necessary.

2. Hook up the trailer and make the electrical connections according to
the trailer manufacturer’s instructions.

3. When a trailer with electric brakes is plugged in, the TRAILER
CONNECTED message displays in the instrument cluster message center.

4. Use the GAIN adjustment (+/-) buttons to increase or decrease the
GAIN setting to the desired starting point. A GAIN setting of 6.0 is a
good starting point for heavier loads.

5. In a traffic-free environment, tow the trailer on a dry, level surface at
a speed of 20–25 mph (30–40 km/h) and squeeze the manual control
lever completely.

6. If the trailer wheels lock up (indicated by squealing tires), reduce the
GAIN setting; if the trailer wheels turn freely, increase the GAIN setting.
Repeat Steps 5 and 6 until the GAIN setting is at a point just below
trailer wheel lock-up. If towing a heavier trailer, trailer wheel lock-up
may not be attainable even with the maximum GAIN setting of 10.

You may have an wheel to adjust the gain rather than push buttons - but same idea.

 

I think the responses kind of went down two different channels as I interpreted the OP's post asking how to know it was working, not how to adjust it. Maybe others did the same. Of course, after you know it is working, you still have to adjust it, so it is all good.

Steve

 

Steve, you are correct - responses drifted a bit from the original question - but for me - and that is just me - the only way to really test to see if the brakes are actually working properly is to use them. All the electrical connections in the world can be tested - and be fine - but the ultimate test is do they actually work properly - which is why I posted the excerpt from the owner's manual about adjusting the gain. Following those simple instructions and he will know if they are working or not. If not he could work backwards thru the connections etc for determine the problem.

In this day and age - how many times have we heard or read about a vehicle with a problem going to the shop and the shop saying everything tested ok. Especially with electrical issues and connections.

So in my defense - and yes I strayed from a strict interpretation of the original question (a little) - but the best way to know if something is working properly is try it and in order to try the brakes the proper gain must be set.

I check my brakes that way when I hook up a loaded trailer - every time.

again my 2 cents - take it or leave it

 

Very good point. A person should know the setting for their empty trailer (assuming a cargo/flatbed trailer), and the setting for an "average" load. Once loaded, set it at your average (so you have at least some brakes), then test and fine tune before making your trip.

 

I will take it!! You and I are in total agreement. My goal was absolutely not to put you on the defensive, but to simply make note of posts going down two lines, both valuable.

Steve

 

Well I know the brakes were working with my dad's truck, so the trailer should be OK, but I have no idea about the controller in my truck. This electric brake stuff is weird to me, only trailers I've driven have been over 40' long and had air brakes.

Your test procedure is actually something I always do with a heavy truck as well, though that's to check that the kingpin is locked no so much that the trailer brakes are working (though it does that too).