Steady ABS light, where do I start?

[Lizard333]

My ABS light comes on, at startup and doesn't go away..... Braking doesn't appear to be a problem. I am very new to these and I am just looking for a little guidance as to what direction I should head. Both air tanks reach 120 psi, and the system holds air.

I have a 1991 ish M923A2 With the ROPS and CTIS.

Thanks again in advance!!

 

[simp5782]

Fuse behind the dash between the blower motor and the ignition switch

 

[foxtrk2]

at my friends shop we deal with these all the time . sometimes the sensors at the wheels are all greased up or too far away from the pickup stator, or the connections at the plugs get corroded, and even computers get fouled. usually a replacement is in order if that's the problem. as far as a fuse id guess if the light is comeing on its not a fuse. you should hear the computer clicking on when you turn on the power switch to the truck

 

[74M35A2]

Simp's advice is sound step 1. The fault code light will illuminate if the fuse is blown, by design. ABS voltage diode on PCB board usually damaged from improper vehicle shut-down switch order. Alternator loses reference voltage, over-volts, and wipes out the ABS circuit board.

This is what is most common. There are other causes, but the above situation is what most face when diagnosing.

 

[Lizard333]

Thanks guys! Ill check it out!!