90 K2500 Brake Issue Abs?

[kris1234]

My brake light keeps flashing 3 times which the OBD1 scanner said “OPEN DUMP VALVE WIRE”. Does anyone know what that would be and how to fix it?

 

(I’m not sure if that is the rear speed sensors) I have a 1990 2500 which is rear ABS.

 

 

 

2^nd question where is the rear speed sensors located & how do I clean them?

 

Thank you

 

 

Kris

[grampadirt]

This should help,notice the wire going to the dump valve...maybe that's the one the code it talking about...

 

also....