78 Chevy K10 - Intermittant wiper switch issue

[DSS]

My 78 Chevy K10 has the OEM intermittent wiper switch option and it has been working fine until recently- Now the washer function will either:
1- not work at all
2- stay on with all wiper settings (i.e int, slow,fast)

Anyone else out there run across this issue before?   Is this telling me I need a new Int wiper switch and/or the control module?

Thanks for the help!

[bd]

If the only complaint is with the washer pump, the pump mechanism maybe broken or worn out.  Power is supplied to the washer pump through its yellow/black wire whenever the ignition is ON.  The washer switch in the dash grounds the pump to energize it, via the dark blue wire. 

Unplug the washer pump and connect a test light between the harness terminals.  With the ignition ON, the test light should illuminate only while the washer pump switch is being depressed.  If the test light illuminates all the time, either the switch is faulty or the dark blue washer pump wire is grounded somewhere between the pump and the dash switch.  [The delay module does not affect the washer pump and has no bearing on pump operation].  If the pump continues to operate more than about twelve "clicks" after its harness is unplugged, the pump mechanism is broken or worn out.  If you determine the pump is the issue, replace it with a newer electric version marketed by Trico (#11-515) and AC Delco (#8-6712).