2018 579 Wipers Only Work on high setting

[BrandonOlsen]

Have a 2018 579 Peterbilt with x15 Cummins. The wipers only work on top 2 high setting. The medium and low settings when used will only move wipers half way then stop. The wiper motor has been replaced. The steering column blinker wiper knob/switch has been replaced. Both fuses were good and also replaced. Any ideas ? Have Cummins insite and ESA.

[Truckdriven]

(06-20-2023 )BrandonOlsen Wrote:  Have a 2018 579 Peterbilt with x15 Cummins. The wipers only work on top 2 high setting. The medium and low settings when used will only move wipers half way then stop. The wiper motor has been replaced. The steering column blinker wiper knob/switch has been replaced. Both fuses were good and also replaced. Any ideas ? Have Cummins insite and ESA.

I had the identical problem on a Kenworth, it was just a bad relay, it's a cheap and easy thing to replace just to rule it out anyway, on mine there was two relays for the wipers

[BrandonOlsen]

(06-20-2023 )Truckdriven Wrote:  

(06-20-2023 )BrandonOlsen Wrote:  Have a 2018 579 Peterbilt with x15 Cummins. The wipers only work on top 2 high setting. The medium and low settings when used will only move wipers half way then stop. The wiper motor has been replaced. The steering column blinker wiper knob/switch has been replaced. Both fuses were good and also replaced. Any ideas ? Have Cummins insite and ESA.

I had the identical problem on a Kenworth, it was just a bad relay, it's a cheap and easy thing to replace just to rule it out anyway, on mine there was two relays for the wipers

Found the problem. The harness from the wiper motor that goes to the relays ( arrow to where it connects to truck ) had a short inside of the harness. It’s a PITA unwrapping it to replace the damaged wire. The outside of the harness had no visual wear. No rubbing, looked normal. I had googled and looked up different sites where people were reporting this issue but with no resolve. So hopefully this helps someone in need

[Rawze]

Probably initially caused by the truck owner allowing the truck-wash places to power-wash under the hood, not knowing any better.

Power-washing things under the hood + those connectors = eventual wiring issues with the wiring harnesses... especially where your arrow is pointing.

Here is a similar post for problems in that same connector/area ...
ref: http://rawze.com/forums/showthread.php?t...1#pid12551