Re-wiring the Old Pete for ABS trailers

Generally speaking trailer ABS is powered by 12 volt power on the centre pin of the trailer plug. This was done so old trucks could pull new trailers and vice versa. I don't believe you need to retrofit any lights to your truck since it was built long before ABS was mandatory. Someone will correct me if I'm wrong though I'm sure.

 

The newer abs trailers will work off the stop lights if no power to the center pole on the plug on the older trucks. No need to do anything to your tractor.

 

mslashbar is correct, but every time you step on your brakes, the ABS warning light will come on for a few seconds. It will also not be able to stay on if there is a fault unless you're holding the brakes. The ABS will also not function if your brake light fuse blows. The ABS light coming on every time you hit the brakes could draw unneeded attention

Since you are rewiring the truck anyway, it wont be hard to add ignition power to the center AUX pin on the tractor, so I'd just do that. Then when you key on, the trailer ABS will go through a self check and turn the light on for a few seconds, then stay out unless there is a fault. More importantly, if there is a fault, the light will stay on even after you release the brakes.

If you already have a AUX switch on your dash and need it for another trailer, you could leave it and just remember to turn it on when you pull ABS trailers.

 

Be careful here. Im less remembering the pigtail set up. Two things. One provides life (Power) and the other can take it away inside that pigtail. I cannot emphasize how much power flowing through there. Be very careful Sir.

 

If I may be allowed to speak to my own ABS experiences in a heavy tractor trailer, when you are confronted with a problem and need to stop now. Your service brake will kick in and usually people take it to the floor or nearly so.

You will have a yellow light in your left hand mirrior from the ABS situation light about 4 feet ahead of the ICC Bumper on the trailer. Your Dash will display the Tractor;s own ABS system. The entire tractor trailer is going to purr in a monstrous way as the 18 wheeler's computers work on just one task modulating and removing brake drum (Disk etc) Pressure off just enough to keep the wheels rotating.

I cannot emphasize how scary and awesome that Purr or Buzz is going to be for you the first time you panic kick in the ABS. (I use the word panic to demonstrate the behavior required to let the computer see that you need to stop right now.) and you will see that your wheels continue to rotate thanks to the ABS allowing you to steer.

You will lose YUGE amounts of secondary/primary air at a horrendous and truly mind blowing rate, if there is anything to consider the braking problem will be over with either a Smash or a Avoiding or somewhere in between. You also will have left a individual set of marks all over that pavement to help you remember and commemorate the event for a few months every time you pass that way in your future travels.

I have used ABS a few times in the rig and I have to tell you it is a edge in battle against that VW Rabbit filled with 4 or 5 men who stopped dead in the rain on southbound Cross Bronx (I-95) in a 6 lane section where the Throgs Neck Bridge Junction set of two lane ram is there on one side and another set of to lane ramps on the other side a short distance. Staying in the middle allows you to access to GWB shortly.

The Rabbit 4 wheeler was executing what is called a hit me sue you insurance scam, first made popular in California The trick is to position the car inside a known distance to where the 40 ton 18 wheeler has no chance to stop without hitting said vehicle with enough violence To whiplash everyone in it (Which pays off big time because medical resourced are deployed to attempt to prevent paralysis to the "victims".)

Because the VW in question failed to take the idea that I was equipped with a full ABS package on both Freightliner Century and a Great Dane Reefer where it sat in the middle lane in the heavy rain, approx 2 inches an hour with ponding beginning on that junction area and 50 degrees. Because I noticed that this particular car's behavior was totally and completely off compared to all other cars that passed up until that particular point in time.

It is also very fortunate that the VW Rabbit (Some of you young ones do not understand just how useful these little cars were back in the day. If you had a Omni, Golf GTI and those kinds of smaller cars with huge brakes big horse power and good tires and a huge stick you could literally raise some hell with those wonderful cars zipping to work around the gridlocked BMWs The M3's would break from the herd and follow you.

Anyhow.

I passed the car on the right. 4 or 5 frowning heads eyeballed me all the way by. I developed a battle plan in which I would mash the car against the upcoming brick wall either on the left or on the right, which awaited us just pror to the GWB. I had already positioned myself in the now two lane road becoming three for the brick canyon of the GWB approaches prior to the one far long ramp that People who had to choose for the lower level or upper level. My position is now in the far left.

Rabbit caught up and just as he began to pass on my right, his speed picked up with intent and I smoothly... with emphasis on smooth movement eased right. He automatically found himself on a ramp.

Of all the things Ive done that was rather risky that one worked out well. so smooth and up the ramp he went unwillingly. Do you understand? And that particular ramp featured about 3 NYC blocks before he could ever get back on to chase me.

I was in Jersey long gone. Thank you Bendix ABS Systems. I owe you 5 lives saved and one trucker's freedom.

 

One thing I forgot to mention when you're rewiring. The new wiring in the tractor needs to be at least the same size wires as an ABS trailer cord. The ground is 8 gauge, the brake lights and auxiliary are both 10 gauge. The other 4 for the remaining lights are 12 gauge. I remember years ago, DOT was on a kick looking for ABS trailers with black cords. If it has ABS, it needs a ABS cord, which are typically green and say ABS on them.

 

You should have a blue AUX wire behind the passenger side dash in the main harness.. I hooked mine to a spare rocker switch.. I use it anytime I'm hooked to an ABS trailer.. The reaction time for the ABS seems to be a lot quicker.. Lets say I had to stab the brakes the other day when a older couple pulled out in front of me!! supermiller.com has a complete wiring harness for our trucks under Schematics..