abs light comes on at 65 mph
 

Hi All,
Can you help me with this one? I have 1988 300 E 100k. The ABS light comes on exactly at 65 mph. When I drive around town it never comes on (sure if I tried to drive thru downtown at 65 it would come on) but on highway as soon as I hit 65 mph that's it. I checked all three ABS sensors and cleaned them (They were not really dirty) but it did not help it. I guess if it was one of the sensors was bad I would get the light on at much lower speeds.
Does anybody have any suggestions?
Thanks
Vlado

I would jack-up the car & measure the circumference of all 4 tires very closely.

Also the charging system may act up at highway speeds, too much voltage can drive the system crazy.

Thanks for your suggestion. Today I will measure circumference.
It makes sense because I bought this car with all tires different brands.
Vlado

Rolling radius with car on ground is the critical one. Check the tyre inflation pressures too - that has been known to cause this.