Oil pressure and high temp light staying on

I say this again..... I wish that I could work on 99 Freightliners with Series 60 all day, every day. This is simple troubleshooting for a shop with a laptop or even an old prolink. A multimeter would even do. Get to a shop that knows what the hell they are doing. That truck and engine combination has been around for 25 years.........engine harness. More than likely closer to the connector at ECM.

 

Sounds like you got yourself between a rock and a freightliner, dryva. This what you goin do. Take that son of a mitch on down there to your local freightshaker dealer. When you check that dinosaur in, tell them you want the oldest guy back in the shop to look at it. You want somebody older than that truck to look at it. He probably worked on some fld's quite a bit back when he had dreams and aspirations. His name will be darryl or harvey or something. When you pick that money machine up 3 weeks later, be sure and pick up some lube on the way, and I ain't talking about heavy duty grease. Tissues too. Look for the smallest fellar in there to pay the bill to. He'll take you in the back some place nice and quiet. You'll survive and will regain your pride one mile at a time.