My anti-loc light has been on since I bought this 87. I've done a lot of checking, found some corroded conections down in the pit & fixed them. Today put in a different computer & hooked up the battery & the light is still on. I have the FSM & it did'nt help much. I took it to a very reputable shop & even with their Bosch adaptors they could'nt read the codes. Anyone with ideas what to try next would be greatly appreciated. Everyone says I should be able to hear the pump. I don't. Is there a way to check the pump?

 

my 86 has same problem found a cable that is broken i think goes to the brake caliper in the back not the speedo im sure thats my problem just havent fixed it yet found it while under car working on something else

 

There are no codes stored on the '87 ABS. Those mechanics are looking for codes that do not exist on your car. This tells me they have little C4 experience. ABS code storing began in '90, ABS began in '86.

If you are using a multi-meter and getting all the right voltage feeds and continuity checks as outlined in the Shop Manual wiring diagram, all 3 relays test good, and fuses are fine, then you must have a bad ABS pump (motor) since you are not hearing it prime up when you start the car and reach 4 MPH.

At some time before my ownership, my ABS compartment had been flooded with water up to the top. Everything was trashed. I scored an almost new ABS pump and computer with relays and wiring harness on ebay. With this and fixing a cut main voltage feed under the car (thick red wire coming from the junction block near battery) my ABS light went out, and my ABS pump now comes to life with each self test upon start up at 4 MPH.

So crack that shop manual back open again and bust out the multi-meter. Make certain that all 3 ABS relays are good (voltage and terminal continuity checks), and all the right wires have the right voltages at the right times all the way from the main feed fuses (Brake, Guages, Stop/Haz and INJ 1 fuses). If all this passes then it's has to be a ABS dead pump since you already swapped the ABS computer for another. The shop manual has a voltage, resistance, and continuity test chart that you can use with a multi meter to check each of the 3 ABS relays and all of the wiring to and from. It even has continuity checks for for the abs pump motor itself at the relay terminal points on top. This tests the internal windings of pump motor itself. A failed test here will tell you right off the bat that the pump motor has an internal break.

Everything you need to diagnose this thing is right there the book with the troubleshooting tables and ABS wiring diagram. And you don't really that special ABS tester that almost few GM dealer even carry anymore either. It's all about process of elimination. It's almost as important to know what it isn't than what it is, so you aren't just throwing parts at the problem guessing. If every wire, voltage feed, and relay check out with your multi-meter, then the only possibility left is the ABS pump itself.

Pump Motor Relay: Bosch# 0 332 002



Solenoid Relay Bosch# 0 332 205 003


Module Relay Bosch# 0 332 512 007

 

When I had my 86 the ABS light would come on. Turned out to be a slightly loose wheel bearing. This had just enough wobble to effect the gap on the wheel sensor and trigger the light.

 

Thanks Pacer....The pit where all the stuff in it is appears to have water lines in it. So it looks like it was flooded at some point too. That would explain the corroded connections I fixed. That is why I bought the computer on e-bay this week. I'll try to do the motor test. I bet thats it. Now I have to find a used one at a reasonable price. There are'nt any on e-bay right now. Thanks again....I'll let you know what I find.

 

Did your pump still prime though?