Like many folk here, my ABS light decided to turn on. A trip to the dealer would have solved the problem but would have drained the checking account.

First thing. Search the forum. Lots of excellent information was waiting there. Most of the ABS problems that were reported ended up being related to the rear ABS sensor that is mounted on top of the rear diff housing.

The Ford service manual has some basic steps.

First is to check to make sure that the brake lights work. Evidently these are tied in to the ABS system. In my case they worked fine.
Second is to check fuses 11 (10 amp) , 22 (60 amp) and 23 (60 amp) fuses. These are in a fuse box under the hood near the master brake cylinder. These were OK.
Next was to do a visual check of wiring leading from the rear brake sensor and from each front brake sensor to the ABS module that was located under the hood. Nuts - everything was OK.

The next step is to read the ABS codes. Here is where the decision point is. Some folk are lucky enough to have an auto parts store that will read the codes for you. No such luck here.

Time to look at picking up (or borrowing) a code reader. The Auto Enginuity has good reviews here but requires a lap-top computer. This old geezer only has a desktop. A second choice is to look at an OBD2-CAN capable reader. The Innova reader was recommended by folk here.

$190.00 was the damage. 10 minutes later the code reader reported a C1236 code. The Ford service manual lists that code as "no signal from rear speed sensor" error. A $26.00 sensor is on order.

I guess that I really needed to get a code reader anyhow. Maybe I'll be forced to get a laptop and use invest in the AE system.

For information, this is the only problem that I have seen since the truck was purchased. It has proven to be totally reliable. No expenses other than what is expected (regular oil changes, fuel and oil filter changes, etc). Maybe 26 bucks in repair parts and the cost of a code reader after 5 years of use is actually very reasonable. Now I get to play with the code reader...

Lou Braun

 

My ABS light comes on every now and then also.

However, it doesn't just 'come on'. I can be going down the highway at 70 mph with the cruise control on and all of the sudden the cruise control shuts off, the speedo and tach drop to zero for just a second then everything, except the cruise is back to normal but the ABS light is on.

This happens more often when I'm on the expressway and have been going for 10 or 20 miles or so. But not always.
It almost always happens when I'm towing my camper with the cruise control on.

I think I need to go through the list of things Lou Braun did to narrow down my problem.

 

My ABS light went on after a trip out to the desert off road. It comes on sometimes, and sometimes the ABS system activates when comeing to a stop.

Now I know about the sensors and havent checked them out yet because I dont drive my truck very often.

My question is: Dosent the rear ABS sensor on the rear axel also send signals to the speedo? If it was bad wouldnt the speedo also be giving me problems?

I will have to check out the sensors first with my VOM and see if I'am getting signal. If the signals are good then I dont know. Maybe a short in the wiring.

I'll be pulling a boat out to the river in a couple of weeks and dont want to make a stop with the ABS activated.

 

I've never had any "bad experiences" with the braking system when the light was on. Actually, besides the light coming on and the gauges dropping to zero for a second I wouldn't know anything happened if it occured when the cruise control wasn't on.

 

Mine comes on anytime the batteries have a low charge or the alternator is going out. Just a thought

 

I think I forgot to mention, the brake pedal will pulsate sometimes when coming to a stop.

 

A bad front wheel bearing will also cause the ABS light to come on. Jack up the front end and check for play in the front bearings. Brakes pulsing could be a sign of something going on with the bearings, too.

 

Ok, I just checked the front ABS sensors with my VOM. Passenger side shows voltage, drivers side zero nothing! I will hit the parts store Monday.

 

The Innova is a nice tool. I have used mine for a few years now. What's great is it also works on the GM models so it covers all my cars. I have more than paid for this gizmo the 5 or 6 times I have used it. It also has some fun things like the real time capture...turn it on and take off down the road and then dump that data down to your pc for further analysis. It's cool.

 

Here's how I checked the ABS sensors with a VOM.
YouTube - ABS LIGHT

 

If you can get one clip in there, you could just ground the other to the frame instead of puncturing the insulation.

Mike