Brake Controller Set Up - Tekonsha Primus IQ

mcman56 wrote:
I'm inexperienced with trailers and just installed a Primus IQ and used it with a newish trailer that likely was never towed with the brakes active. All I did was set a recommended boost per the manual for trailer and tow vehicle of similar weights. A short maybe 10 minute ride around suburbia with a top speed around 45 mph followed. There were lots of stops. It felt OK but I have no experience with trailers larger than little dirt bike trailers. When I got back, I could smell brakes. Placing my hand on the wheel by the brakes, they were noticibly warm to hot. Could this be normal for a first time activated brake system? Is boost really a good idea or could that be the issue? 2002 Silverado with tow package, Fun Runner toyhauler, estimated 5000 lb

Did you pull the manual lever, to tell how much trailer brakes you had? at 25 MPH, pulling the lever with no pedal input should give you a pretty good jerk. If you don't feel anything, dial in some more. If the brakes lock up, Let off just a tad.

As for the boost. That just activates the brakes for a brief second. IF the controller does not feel the TV slowing. It releases the Trailer brakes. In other words. The boost just helps the TT brakes start at the same time as the TV brakes. Once braking has started, The controller "feels" the TV decoration and send the needed power to the trailer.

I did not read about the manual lever until I put the trailer away. I'll do that next. What I'm really concerned about is the hot brakes. This was just an easy roll around flat surburbia. What will happen in the mountains?

mcman56 wrote:
I did not read about the manual lever until I put the trailer away. I'll do that next. What I'm really concerned about is the hot brakes. This was just an easy roll around flat surburbia. What will happen in the mountains?

If the brakes were too hot to touch. You need to get them checked. And if you set them cold. You may have too much power going to them. they really need to be adjusted warm. They work a lot better after they warm up.

IF you do mountains right nothing will happen. When you start down the mountain. Pull the transmission back to a lower gear, depending on the steepness of the grade. You may even need to go all the way to 1st gear. But do it BEFORE you start down, do not start down faster than the slowest speed you will be going. IF you have a gas engine, doing that will hold the TV, and TT back, and you will not have to use the brakes so much. NEVER, NEVER, NEVER, tow in the mountains in overdrive.
Do NOT ride the brakes, use the gears. IF you have diesel. This won't work so well unless it has some sort of exhaust, or trany brake.

go slow, use the gears. You will be fine.

I use a an IQ with my 9000lb 5'er. Have had zero issues and it works great. You need to do the 25 mph set up for the gain. Then find the boost setting that suits your trailer. I run B2 90% of the time. If I'm running thru town for a long ways with a lot of stop and go then I just drop the boost to B1. Too much boost and the trailer brakes drag at the end of the stop.

With your light trailer I would venture that the boost would be 1 or 2. Couldn't tell you on the gain.

Are saying the trailer brakes are real hot? Or the trucks? If the trailer brakes are real hot and you didn't do the 25 mph test to set them up then it's possible you have way too much gain or boost dialed in and the trailer brakes were doing most of the stopping. The 25 mph test is very omportant in setup.

The TV is a Silverado with a 5.3 gas engine. By itself, it coasts super easy down hill so must have some kind of torque converter disconnect. It does have a "tow range" selector on the lever. That may disable overdrive. By hills, I mean I80 from near Tahoe down to Sacramento. I don't know that anythign is super steep but you lose 5500 feet in about a 1 hour drive so there is a lot of down..

I did not do the 25 mph test so that is likly it. I do that the next time I get it out.Based on the literature that came with the controller, I used b2 so maybe I should also try b1.

Thanks for this input.

mcman56 wrote:
The TV is a Silverado with a 5.3 gas engine. By itself, it coasts super easy down hill so must have some kind of torque converter disconnect. It does have a "tow range" selector on the lever. That may disable overdrive. By hills, I mean I80 from near Tahoe down to Sacramento. I don't know that anythign is super steep but you lose 5500 feet in about a 1 hour drive so there is a lot of down..

I did not do the 25 mph test so that is likly it. I do that the next time I get it out.Based on the literature that came with the controller, I used b2 so maybe I should also try b1.

Thanks for this input.

Does it have a gear selector? If so, use that down hills. It's bound to have a 1, 2, or 3. Don't just put it in drive and leave it there in the mountains. Use the tow haul if it has it.
Actually it sounds like you need to read your manual so you can learn about how your truck works. When towing a trailer. YOU really do need to drive the truck. It not like riding around unhooked. Now YOU need to drive. You have to learn how to stop it, how much to swing, how to hold the wheel VERY still. Learn how far it is from you to the rear of the trailer. Towing is a whole nother world. Learn how your truck behaves. Play with the gears. DRIVE

I went through the controller set up and it seems OK now. The default power setting was 13 so that must have been my hot brake issue. Set to 6, the brakes do not lock with the manual/ 25 mph test but I can feel it slow down a bit.

I checked the manual and the tow/ haul mode still seems to use overdrive. (It does not say it does not.) I'll use that plus set in 3rd for down hill. I was on the freeway today and down the largest local 50 mph hill and it seems OK. I'll be driving it but want to be prepared as possible to avoid newbie issues because I did not know any better.

On this same note, is there a way to safely test the emergency breakaway switch?

Thanks for all of the input.

You really need to set it at 25mph so they lockup and then back it off till they don't. Also make sure you select the right boost setting. B won't do anything and B3 may be too much. Sounds like you need to fine tune it.

If you dial out too much TT brake you may find yourself using one of the emergency pull outs when coming down the mtn.

Even set to the max power of 13, I do not think the trailer wheels are locking up at 25 mph. This has dual axles with the brakes on the rear axle. Can it be hard to tell if they are locking? With the window down and listening plus looking in the mirror, I see no signs of lock up. I do feel a strong deceleration so they are working to some extent. I was concerned about coming down from 5500 feet but by staying out of overdrive, I only had to touch the brake a few times for very short time periods. (Thanks for that recommendation to stay out of overdrive.) The trip went well.

But..... after getting off of the freeway with almost zero use of brakes there were a few miles of surface streets with 4 or 5 red lights to stop at. When I got home, I got a slight scent of brakes. The wheel hubs were also pretty warm on both sides where the trailer brakes are located. Do trailer brakes tend to run hot/ warm? The trailer is new if that is a factor. Thinking back, the slight brake smell could have been coming from the TV. It is an old truck but new to towing.

To clairify my question, no skidding with the manual brake test seems to be telling me that there is inadequate braking on the trailer. Warm hubs with little brake use seems to be telling me there is excessive braking on the trailer. This is the part I find confusing.