84 K20 wiper problem

[Leberneck]

So When I turn on my windshield wipers they work at one speed...Very Slow. they seem to barely get up and going after first starting my truck and after about 5 minutes they are just dragging along the Windshield. i have changed out the wiper motor and got no new results. what is the issue?

 

[chengny]

How is your overall system voltage? Battery and alternator are good? Sluggish wiper operation is often the first noticable sign of low voltage.

Wiper linkage may be binding up. Listen under the intake cowl while the wipers are running. Hear any thumping or grinding?

The wiper motor is grounded to the frame via a copper strap that connects to one of the gear box mounting bolts. It is often painted but you should still see it. Make sure that the threads (and the underside of the head) on that bolt are good and clean. Use a tap and chase the female threads in the frame for that bolt as well.

 

[89Suburban]

 

[Leberneck]

Right now i am Living in Japan but i will be moving back to the states in May for my next duty station and will check out what you have suggested. i do know that the battery is out of a toyota 6 banger. i dont know if that effects anything because again, im not near my truck right now. i didnt notice any banging under the cowl. so i am sure it is either the voltage or wires. i just dont want to invest in unnessacery materials. Thanks for your response! it was very helpful. i will update when i get home in may