Leelund6 Posted October 3, 2020 Share Posted October 3, 2020 Well she's been running for about two months and all of a sudden the antilock light comes on. Can't seem to find much about it. Hoping some one here can enlighten me. Read something about pulling a code from the harness. Any body got some info to throw me. Thanks in advance.. lookin for a bone. Link to comment Share on other sites More sharing options...
old55pete Posted October 3, 2020 Share Posted October 3, 2020 Dont get me wrong, what are we talking about? A bullnose ( 80-86) does not have ABS. Is the BRAKE light on, on the dash? If it is, it could be a stuck switch on the parking brake. It could be the proporting valve stuck in one side or the other because of a brake problem, meaning something is out of balance in the brake system. Link to comment Share on other sites More sharing options...
kramttocs Posted October 4, 2020 Share Posted October 4, 2020 Dont get me wrong, what are we talking about? A bullnose ( 80-86) does not have ABS. Is the BRAKE light on, on the dash? If it is, it could be a stuck switch on the parking brake. It could be the proporting valve stuck in one side or the other because of a brake problem, meaning something is out of balance in the brake system. OP is working with an 87 Never too late to add a signature Link to comment Share on other sites More sharing options...
85lebaront2 Posted October 4, 2020 Share Posted October 4, 2020 First, the parts store code readers will not work on these older trucks. Second you have to leave the key on once the light comes on as the system does not store codes. The only way I can get these for you is by doing a screenshot of my AllData. Here are the code retrieval procedures, once you get the codes I can give you the diagnostic tests for them. Before you get deeply involved, try pulling the sensor on the rear axle and see if it has a bunch of steel filings stuck to the magnet. Link to comment Share on other sites More sharing options...
Leelund6 Posted October 5, 2020 Author Share Posted October 5, 2020 Dont get me wrong, what are we talking about? A bullnose ( 80-86) does not have ABS. Is the BRAKE light on, on the dash? If it is, it could be a stuck switch on the parking brake. It could be the proporting valve stuck in one side or the other because of a brake problem, meaning something is out of balance in the brake system. Oh yea, my bad for sure. She's an 87 f-250. Got her for free out of a field where she sat for over 12 years. Ok, I'll check for filings first thing in the AM and go from there. I'll let ya know what I find. Link to comment Share on other sites More sharing options...
Leelund6 Posted October 5, 2020 Author Share Posted October 5, 2020 Oh yea, my bad for sure. She's an 87 f-250. Got her for free out of a field where she sat for over 12 years. Ok, I'll check for filings first thing in the AM and go from there. I'll let ya know what I find. Well I checked the pick up on the rear end. No metal at all. Now for the fun part! Pulled codes and got, "open isolate circuit". Guess I'll look into that now. Link to comment Share on other sites More sharing options...
85lebaront2 Posted October 6, 2020 Share Posted October 6, 2020 Well I checked the pick up on the rear end. No metal at all. Now for the fun part! Pulled codes and got, "open isolate circuit". Guess I'll look into that now. Ok, here are the next tests based on the code you retrieved: Have fun! Good luck with it. I don't know where you are, but here in VA, the ABS yellow light on won't fail inspection. Link to comment Share on other sites More sharing options...
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