I am trying to help a friend on his anti-lock 1987 300 sdl. The light stays on. We have bled the brakes and replaced the rear pads. Can any one tell me the correct troubleshooting procedure to get the light to go out or tell me what to check? The light will go out if the brakes are pumped up prior to starting car. Thanks Jack

Jack,

I had an 87 also. The front abs sensors bolt into the backing plate for the front wheels. You can look at them from the middle of the car looking out and see if the "teeth" on the inside of the rotors are crudded up. If so I would spray them with brake cleaner. Maybe pull and clean the sensor. It seems like it had one allen bolt holding it in place.

Mine turned out to be worn out cables. The sensor has a coax looking cable that runs up into the engine compartment. It then has a screw connection to more coax that goes into the ABS computer. I found worn spots on my cables and replaced the unit ( sensor and a length of cable).

The third sensor is in the differential and seems to be more stable. Mine was fine and did not need replacing.

Other issues can be bad connections on fuses or relays. Also low voltage possibly from a bad alt.

Chuck