trailer brake controller

dr9672723 · June 14, 2004

Hi all

I would like to install an electronic trailer brake controller on my '03 1500. I remember seeing in my owner's manual somewhere that you need a special harness from the dealer because the logic of the brake switch circuit is different for this year... I vaguely remember someone saying that electrical signals are transmitted via serial communication now... but for brake lights? Come on. Nothing like making a simple thing complicated.

I'm wondering if it's as simple as getting on to the brake light switch as usual, and the owner's manual info is to help the dealer sell a $25 harness that I don't need. Or, am I wrong? Does anybody know if there is a real reason why I can't splice into my wiring as usual?

Thanks for any advice.

Dan

Shaners · June 14, 2004

The modular harness that you buy from the dealer plugs into the black access box behind the the E-brake pedal. It goes in the top row second from the left. You just take the loose wires and then wire them into the wires on your controller. It's very simple and no test light is needed.

You are correct that an '03 requires a different harness than the '99-'02 trucks.

snoman · June 14, 2004

The modular harness that you buy from the dealer plugs into the black access box behind the the E-brake pedal. It goes in the top row second from the left. You just take the loose wires and then wire them into the wires on your controller. It's very simple and no test light is needed.

You are correct that an '03 requires a different harness than the '99-'02 trucks.

They make the harder or more expensive to fix or modify every year it seems sometimes!

SteveCZ · June 14, 2004

This is an extra purchase?

Or is it only extra for 2003 and up trucks?

My 99 came with the harness in the glove box...

snoman · June 14, 2004

This is an extra purchase?

Or is it only extra for 2003 and up trucks?

My 99 came with the harness in the glove box...

no problem with 99

builderpaul · June 14, 2004

I don't think GM made it harder. They made it easyer. Just plug in the harness. No more hanging upside down, under the dash, unbundling and probing wires with a test light. Well worth the $25.00.

The harness comes standard with the trailer package option. Without you may also have to install a fuse.

The 03 harness is different from previous years.

frdfandc · June 15, 2004

The modular harness that you buy from the dealer plugs into the black access box behind the the E-brake pedal.

My salesman GAVE me one. Said I should have received it when I picked up the truck. (My truck came with the towing package)

bigdogs · June 15, 2004

I was told the harness does not come with the 03's (even with the HD trailer package) and you had to buy it separately. Maybe my dealer was just being cheap?

glennbobg · June 15, 2004

Yep,

GM has gone cheap if you are in good with your dealer (which you shold be after giving him 25k ++++) he should give you one otherwise get ready to spend another $30 at the parts counter! DO NOT use one from an earlier model it will work for about 10 minutes!

Glenn

Mort · June 15, 2004

Well my truck has the trailering package and did not come with a harness. For $55 CDN I got the harness, a 7 to 4 pin adapter and a 40 amp fuse for the Stud 1 position in the under the hood electrical panel.

Guess someone made off with mine or the dealer kept it and sold it back to me. Next time I will be sure to ask for one from the saleman!!!

Very easy to install and no hours trying to figure out why nothing works properly. Worth the investment if you ask me.

bigdogs · June 15, 2004

My dealer told me that they no longer come with them so if I wanted it I'd have to buy it... Well I got even as they changed the front lube to synthetic for free

stlmaj · June 15, 2004

03 doesn’t come with a harness (at least mine didn't) you can use an old harness from 99-02 but you have to swap two wires on the old harness. Sorry I can't remember which two but it works great!! If you’re going to buy a brake controller my vote is for the Prodigy and you can get a prewired 03-04 specific harness for $14. Cheaper than the dealer and no wiring required just plug it in and go.

Matt

bigdogs · June 15, 2004

If I was getting a brake controller that is probably what I would get. For now I just tow a little snowbear trailer from home depot with it and even with my Sportsman in it, it weighs less than 3000lbs.

I know the wife would like to get a horse trailer sometime which would require one or else use hydraulic brakes (think one of them said it did that in favor of electric)

Mort · June 15, 2004

I am not sure if there are advantages or disadvantages to hydraulic trailer brakes but I have heard stories of some problems with them and stock systems being able to push the volume of fluid required and connection problems. I have never used that system and think that it is too fussy and probably expensive for a small trailer.

My 2 horse bumber pull is wired for electric and it seems perfectly adequate. It will drag the tires on dirt or gravel if I have it set too high. I am not sure if you will find the smaller horse trailers with hydraulic brake systems or not but I would think that you would find the electric brake systems work just fine for that application.

AHHH horses - eat money and sh$t work - gotta love em.

bigdogs · June 15, 2004

Thanks Mort,

It was one trailer she got a brochure on that used the hydraulic brakes, most of the ones I have seen use electric too. She was looking at 2 horse straight load but can't be too small as they are not that small, one is even a draft cross. She's the one that rides them, my ride is a Sportsman 700