Fast Idle Antilock light on
 

'87 560 SEL 125K
Car periodically has antilock light on with fast idle 1,200 RPM. Shut car off, restart ten minutes later will have antolock lock light off and a normal idle. Any idea whats going on here? Happens approximately every fifth usage of vehicle.

I know the answer to this question is used alot but your problem is the overvoltage protection relay.

I may very well be mistaken, but I don't think that this engine had the overvolt replay problem.... :confused:

All cars that have a fuel computer starting in 1980 have some sort of voltage surge protection! Check the over-voltage fuse on this model. jump starting will blow the fuse. About a foot away from the brake booster.