1997 freightliner classic dies

Need to plug everything in. Start it up. Let it die out. Then pull codes. It’s the wires or sensors on one of the two.

 

I get it, but i mentioned it because it happened. All sensors are 5v, and the shorted fan solenoid sent 12v back into the CLS Module, causing mayhem.

Simply unplug it and you can eliminate it as a possibility

 

My memory may be wrong. Seems on my 99 if I unplugged the coolant level sensor (on the tank) , I had to jump the pigtail plug with a paper clip to make it override the shut down, and run. I’m my current 2000, it runs with it simply unplugged, except the yellow cel stays on. A paper clip fixes that.

 

You can set to either check engine light, or shutdown. Unplugged sensors should give a high voltage fault, only turning on the CEL.

I've narrowed down issues with stop engine lights that way when I didn't have the laptop with me. Just unplug the sensor. Get a ck engine light with no shutdown, fault found.

I

 

Original post says temp goes to 250. It’s normal to go to 250, and drop back down when key is turned to the on position. I think the whole problem is the temp sensor or wires.

 

Maybe @jamespmack has some insight

 

Makes sense. My coolant level sensor has always given me grief. I changed it a few times. For a while it shut down every time it got wet. Every Truck wash, and a couple times in heavy rain. I’d unplug it and run till it shutdown again. Then plug it in, and it was fine till it got wet again. Once it was the plug. Last time, I bought a new plug, spliced it in. Turned out to be the sensor. My yellow cel is burned out. Just happened to catch it while active (red). Talk about aggravating. I often want to put in a switch, to turn it off/ override it at will. It’s given me so many problems, since I bought this Truck 15 years ago. Always intermittent. The bad wires were to blame for a few sensors. Each time thinking it was fixed. It’s always been a problem on FLDs. Just about drove me crazy. Only a matter of time till it needs a sensor or a plug again. Zip ties to the upper radiator tube help. Electrical tape around the plug/wires to keep it from wiggling helps. But eventually heat or film on the probe causes it to act up again. Between the fan blowing it around and the wires running along the head and getting hot. It never ends.