I just bought a 92 Honda Accord. What would make the ABS light stay on all the time?

The ABS control unit turns on the ABS indicator light, when one or more of the below described abnormalities is detected. This is only a partial list:

. When the operating time of the motor in the power unit exceeds the specified period.
. When vehicle running time exceeds 30 seconds without relasing the parking brake lever.
. When one of the rear wheels is locked during running.
. When absence of speed signals from any of the four wheel sensors is detected.
. When the activation time of all solenoids exceeds a given time or an open circuit is detected in the solenoid system.
. When solenoid output is not detected in the simulated anit-lock brake system operation carried out during running at speeds of 6 mph or more.

To check the indicator light bulb, the light is activated when the ignition switch is turned on. It is turned off after the engine is started, if there is no abnormality in the system.

It's very important on ABS systems to regularly change the brake fluid with an ABS approved fluid, such as Valvoline SynPower Brake Fluid. Non-ABS brake fluids are too thick and will damage the system. Corrosion in the ABS system will likely require replacement and generate an eye-popping bill. Regular fluid changes are the best way to prevent this from happening. The fourth item listed above is prevented by regularly removing the ABS sensor on each wheel and cleaning with a spritzled rag (do not use compressed air).