Trailer ABS cycle not working.

I'd first check to see if the trailer light bulb is good.
Some trucks will not illuminate on the dash for a trailer abs problem. Most trucks the dash abs light is just for the truck abs.
Check your pigtail, make sure there is power going to the trailer abs. Usually center pin. Should have power whenever the key is on.

 

Does the ABS light on the trailer cycle when you step on the brakes? It uses the center pin for key switch power. As a backup, it gets power from the trailer brake lights. In 2006, your tractor is required to have a dash mounted lamp for the trailer ABS. It should cycle when you key on. Also when you turn the key on, you should hear the ABS modulators clicking on the trailer (may take a 2nd person to listen at the trailer), if the ABS modulators are clicking, then you probably just have a blown bulb or wiring problem to the warning light. I don't think that it's your problem though unless the dash light is also burned out. If the trailer bulb fails, the dash light would still work. The dash light is activated through a PLC (power line carrier) from the trailer ABS. If the trailer ABS is not powering up, neither of the warning lights will work.

The first step is to make sure that you have power to the center pin on the tractor 7 way. If you do, then you need to verify power and ground at the trailer ABS. The trailer ABS is 4 wires.

Red - Brake Light Power
Blue - Key Switch Power
White - Ground
White/stripe - ABS Lamp on the side of the trailer.

Most of the time, we find corrosion in the harness. There is usually a break away plug from the 7 way cable for the ABS going to a smaller 5 or 6 way plug to the ABS harness. We find many of these greened out and eliminate them. We just hard wire it with solder and heat shrink. The plugs don't handle the north east winters.

Once you get it fixed, for future reference, the trailer ABS lamp should come on for 3-5 seconds every time you key on. If it doesn't, then there is an issue. DOT is cracking down on this more and more.

 

This sometimes works for me. If you try this and it doesn't work, call the shop so you can get them to fix it. Anyhow, when I am hooking to a trailer and the glad hand connections are rusty and hard to hook up to, I look to make sure the rubber washers are in good shape. If not, replace them. Then, take your P.B. Blaster and squirt a small amount into the metal part of the couplings, both that of the truck and trailer. Then, there is always a little extra P.B. Blaster liquid on them, take your gloved finger and put a small amount onto the washers. I think a lot of the time the abs light comes on on the dash is simply because the air isn't sealed off well enough. The P.B. Blaster accomplishes this. A lot of the time if your trailer is dragging and affecting your tractor's uphill performance, this will solve it.

 

PB Blaster in the air line? Really?

Maybe you don't realize how the ABS system works. It doesn't work using air. And it doesn't give a light because of any air.
ABS watches the turning of the wheels by magnetic pickup (electrical). When a wheel locks down, it releases some of the air pressure going to that wheel by a modulator valve.
Loosing air or an air leak should not have any effect on ABS.
Most ABS light problems are from not picking up a sensor at a wheel or modulator. The modulators are what you here clicking when you turn the key on.

 

I agree with Flightline, the ABS light (or lack of) is an electrical issue, not an air issue.

 

First off, I never said to spray it into the air lines. Secondly, I said that if it did not solve the problem to consult their shop personnel. Thirdly, and sorry if you agree or not, but 60% of the time I do that, the light stops appearing on the dash.

 

AllBidness: I'm sorry if we offended you or struck a nerve. Please keep posting.
ABS is probably the biggest mechanical trouble maker for trucking and now DOT has found it to be an easy money maker.
Us O/O prefer consult the shop as last result because it can be costly if you can lucky enough to find a shop that will give advise.

One of the newest thing I've leaned that might set off ABS light is having different sizes tires on the truck. I don't mean just the rated size but a pair of new ones on one side and almost wore out pair on the opposite side. I was suprised to be shown this can be almost 4 inches per revelution.

 

on my 2009 cascadia i drove 2 years before a mechanic casually mentioned theres a dash switch to power abs on trailer .its the first truck ive driven with that aux trailer switch needed for abs . before it would temporary light abs symbol on brake applications or while jaking on high .jakes light up brake lights on that year

 

When I turn ign.on I don't hear clicking sound on trailer and light is on all the time?Is possible relly went dead or?Thank you!