I am posting this hoping to find some answer's for my husband. We have a 2000 frieghtliner with a detroit 60. This truck runs well and then starts a shutdown process;

First: Fan goes on does not turn off
Second: Engine light and oil Light go on(while buzz sound)
Third: engine shuts off

He has changed fuses but they keep getting blown... he does not have a diagram that will actually say what each is for.... and may be we can find out if it is an actual relay, a part. or wire.... pretty lost on were to get this information...how to read its code... or what is the most possible options to do first and check and change... BTW oil level is fine....

You might see if you can find a mechanic who can connect to the trucks ecm. The cost is usually minimal and may tell you what is going on. Does the temperature go up prior to the lights and fan coming on?

If you have the code post it here. Some of us have the sheet that shows what the code is. On my old Freightliner you push the override button twice while the truck is idling and count how man times the light flashes. It's a 2 digit code so the light will flash once or twice for the first digit, then it will pause for a second and flash 2,3,4,5,6,times.

Low coolant will cause shutdown too.

Detroit Diesel Code

The DDEC diagnostic systems uses two types of diagnostic trouble codes. Active codes are conditions that are presently occurring. Inactive codes are faults that have occurred previously.
On the DDEC IV system, active codes will flash on the Stop Engine Lamp (SEL) in numerical order when the diagnostic request switch is held. If there are no codes, code 25 will flash. Inactive codes will flash on the Check Engine Lamp (CEL) in most recent to least recent order when the diagnostic request switch is held. If there are no codes, code 25 will flash.
On the DDEC VI system, active codes will flash on the Red Stop Lamp in numerical order when the diagnostic request switch is held. Inactive codes flash on the Amber Warning Lamp (AWL). Flashing codes provide a four-digit number,