I have a 2010 Peterbilt 387 with a Cummins ISX 450ST CM 871 My windshield wipers are not functioning properly. They turn on (when they are set to off) when I have my lights on and activate my turn signal and sometimes when I hit my brake. They also turn off (when they are set to on) when I activate my turn signal. The windshield wipers are controlled on the turn indicator lever on the steering column and the lights are controlled on the left side of the dash just behind the turn indicator lever. The fastest setting for the wipers has never worked properly. I have replaced the relay and checked all of the fuses and everything looks ok. Does anyone know what may be causing this? Thank you in advance.
All that stuff runs through the turn signal switch so possibly there is a short in there. The are little copper contacts that can break and bounce around shorting other contacts out. Another possibility that stuff also runs through a body control module which is like an ECM for accessories. I would say one of the two. It takes special diagnostic tools to check the BCM. Is the truck still under warranty? Take it to the dealer.
It is not under warranty and I try to stay away from the chiropractor (dealer) as much as possible. You see, when I have money in my wallet, it causes me to lean in one direction when I sit down, which in turn is bad for the alignment of my spine. The dealer will empty my wallet, straightening the alignment of my spine in the process. I will check into those two items you mentioned.