These Kenworth PACCAR Instrument Clusters have a common problem with the air gauges. Usually the secondary air gauge stops working first but sometimes the primary or both will stop working at the same time.
Send your cluster to us and we will repair this issue within 24 hours of receiving it and send it back out to you. We will also give the entire unit a good cleaning inside and out, and re-calibrate all gauges upon reassembly. As with all of our repairs on commercial equipment, we offer a 2 year warranty on this service.
For more info or to order go to https://forelleco.com/shop/ols/categories/kenworth