Hello Karl! Welcome to JustAnswer.com. My name is XXXXX XXXXX X am here to assist you.
First I will need some information from you. 2 orXXXXX When exactly did this problem first manifest itself? Was any other work performed about the same time as this started happening? Any warning lights on dash?
Did the ABS lamp go out after that repair?
When you say the ABS light comes on when you start the truck... It comes on and stays on, without moving the vehicle? I'm sorry for stringing these questions out, my mind wasn't focused for a minute or two.
Ok. The reason that question is important is because your truck's abs computer will start from scratch every time you start the truck. If the light turns on immediately after you start the truck and stays on without moving the truck, the failure is what is known as a hard code, or a constant failure. Because of this, it will be necessary to have the truck's computer scanned so as to be able to "see" what the truck "sees". Once you have the code(s), you will have a starting point for your diagnosis. Your symptoms are consistent with wheel speed sensor and/or air gap issues however without the code, you would be just guessing. And guessing at this stuff gets expensive real quick. Let me know if I can help anymore. Get the code and I will be more than happy to walk you through the diagnostic procedures if you are up to it!