Installing Electric Trailer Brakes

Bry21317

Chief Petty Officer
Joined
Apr 9, 2002
Messages
552
I have some questions about installing Electric Brakes. The boat is new to me since April, had another boat for over 11 years. So not new to boating, but this boat is alot heavier than my old one. I feel it needs the brakes. The guy that I purchased the boat from, removed the brakes, or something went wrong with them and he never replaced them.

I am going to go with the Electric brakes, which I have already gotten from Nothern Tool.com. My trailer is a single axle, with 12 inch drums on it, now, it just did not have the brake shoes inside. So I am going to use the original drums, as they seem ok, and put the electric shoes inside. There are 2 wires on each shoe actuator (guessing this is what you call it). I am wondering what I wire these up to?

I have a 2003 Suburban with a 7 pin connector, currently I use an adapter to drop it down to 4 pins. I know I will now be using the 7 pin, so I purchased a 7 pin wire and will be wiring this up on the trailer. I also purchased a Breakaway battery/charger/switch that came as a kit. I will be installing this for the safety of it.

I am good with wiring/electronics/fixing most things, so it should not be that hard. I just need to know what wires the breaks will be attached to. Do they get hooked up to the same wire that runs the break lights? What is the large white wire for that is the center pin on the 7 pin connector?

Any help would be greatly apreciated, as I plan to install them this weekend.

Thanks,
Bryan
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Installing Electric Trailer Brakes

The brakes get wired to an electric brake controller mounted in the cab of the tow vehicle. If you wired them directly to the brake circuit the brakes would come full on and howl the tires every time you so much as touched the brake pedal. The brake controller is actuated by the brake pedal, but a sensor (a pendulum of sorts) is what determines how much current is applied to the brakes based on the rate of decelleration. The controller also has a manual control that allows you to actuate only the trailer brakes should you have an unexpected sway condition. It snaps the entire rig straight with a touch of the button. So to answer your question, the ground wire from each brake magnet gets connected to ground. The hot wires get connected together and then connected to the trailer brake terminal in your seven pin connector. That seven pin connector also has a +12V pin that can be used to feed the breakaway battery to keep it charged. You need to check your owners manual to see if your tow vehicle already has a built-in brake controller. Some newer trucks do. Older vehicles do not but if the vehicle already came with the seven pin connector, the wire may already be in place and you should find the brake conector under the dash.
 

Bry21317

Chief Petty Officer
Joined
Apr 9, 2002
Messages
552
Re: Installing Electric Trailer Brakes

Thanks for the information.

The brakes did not come with any at all. This is why I was wondering on this. I will look to see if I have a controller already. I do have the Tow/Haul mode button on my Chevy, and the 7 pin connector already wired into the back of the truck, it was that way stock with the tow package.

So do I just ground the leads to the brakes, which ever ones are the ground ones near the hub? Or should I run a wire back to the harness to ground these?

Thanks,
Bryan
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Installing Electric Trailer Brakes

Ground is ground, but it must be a solid ground. The trailer frame is a better ground than any piece of wire -- BUT, if the rear part of the trailer frame is bolted to the tongue portion of the trailer, add a ground strap across that joint. Bolted joints may not make a good connection. The White wire in your trailer light harness must likewise be connected to the trailer frame. The Tow/Haul mode button on your truck has absolutely nothing to do with trailer brakes. It merely alters the transmission shift points for towing. It doesn't give you more power or any brake action.

If you have an electric brake controller it would be an obvious adjustment, light and manual button somewhere on the dash. You need to leave enough slack in the wires at the wheels to allow for up and down movement of the axle while on the road. Get them too tight and they will be pulled apart.
 

escapade

Petty Officer 1st Class
Joined
Jul 30, 2007
Messages
205
Re: Installing Electric Trailer Brakes

if your vechicle currently has only a 4 pin connector can you change it to a 7 pin connector for trailer brakes?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Installing Electric Trailer Brakes

He already has a 7-pin on the truck. It's wired as shown below. You do need a matching trailer harness.

7PinTrailerWiring.jpg
 

Bry21317

Chief Petty Officer
Joined
Apr 9, 2002
Messages
552
Re: Installing Electric Trailer Brakes

Thanks guys. I found that most people seem to like the Prodigy Brake controller, my local Uhaul has them. So I plan on trying to wire up the brakes this weekend. I also found the connector that I will plug the Brake controller in, under the steering wheel.

Thanks for all your help. I will let you know if I need any more help, as always IBOATS Rocks!

Thanks,
Bryan
 

Bry21317

Chief Petty Officer
Joined
Apr 9, 2002
Messages
552
Re: Installing Electric Trailer Brakes

Ok,
I have one more question. I have gotten one side of the Brakes installed, also ran into bad bearings, so this took longer. The brakes alone would have only taken about 2 hours, I am guessing without any bearing trouble or rewiring all the lights while I was at it.

So I have all the wires hooked up, including the breakaway swith and battery, they are working fine. I just wired up the Prodigy last night. The problem that I am having is the Top right Pin on my 7 pin, OEM harness is not supplying a +12 Volts. Is there a location that I need to plug a fues in for this? It looks to say this in the manual, but it does not tell you where. Can anyone tell me how to make this supply 12 volts to charge up the breakaway battery?

I will be done with the other wheel this weekend, got to get those d** races out to put the new ones in, and these are the worst hubs I have ever seen for this.

Thanks,
Bryan
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: Installing Electric Trailer Brakes

SEEK OUT YOUR OWNERS MANUAL ;)


On my 2003 the fuses are in the dash pannel buy the drivers door As well as the BIG box under the HOOD

The bigger ones tend to be in black box under the hood BUT there is no real logic to there placement :rolleyes:



Tommays
 

Rusty Boater

Petty Officer 3rd Class
Joined
Jul 19, 2007
Messages
96
Re: Installing Electric Trailer Brakes

Thanks guys. I found that most people seem to like the Prodigy Brake controller, my local Uhaul has them. So I plan on trying to wire up the brakes this weekend. I also found the connector that I will plug the Brake controller in, under the steering wheel.

Thanks for all your help. I will let you know if I need any more help, as always IBOATS Rocks!

Thanks,
Bryan

For multiple axles yes a Prodigy is good. But for a single axle a cheap Drawtite box will work great for you.
 
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