ABS light on when hit 70 mph

Hello, My husband had replaced the front brakes on our 98 Windstar, and since then the ABS light has been coming on when we go over 70 mph on the interstate or highway. But the light goes off when we turn off the engine, and does not come back on until we hit 70. Any ideas??? Thanks

Normally when one changes the brakes they have "extra" brake fluid due to the fact that the new pads are thicker. This fluid either spills or is removed manually (recommended). Perhaps he removed a little too much.

I would ensure that the fluid is topped up. Low fluid can trip the ABS light before it is low enough for the Red Brake light.

This does not explain the 70 mph though but I think it is a good first step.