abs problem on 1990 Mercury Cougar

My abs pump will not turn on ,I have rigged a switch to turn it on when i need pressure,I have replaced the abs module 3 times with salvaged parts,also i have replaced master cylinder,sensors, accummalator,abs pump and motor. with salvaged parts.can anyone help?

Asked by for the 1990 Mercury Cougar
junk parts are never a good idea. with all the parts you have thrown at it, you could have repaired it with new and solved the problem for less money.

the module is a common failure and because of this you have put in several that have failed. you should only use new if you want it repaired correctly. put all the wiring back to original and get to a shop for a real diag with a bid.

1 more answer
This may be a case for a diagnosis by anqualified shop with a scan tool or a pin point test to find out exactly what is happening with your ABS system. It could be as simple as a relay failure, ground or a poor connection. Spend the money for a diagnosis, it may be cheaper than throwing parts at it.