Detroit 60 series

There’s also a module in the fuse panel on my Freightliner. It replaces 3 or 4 sensors on ddec4. I forget which ones. It does affect the fan operation. It’s a small box, marked pdmi. Power distribution module. Might want to look it up, see if it could be the problem. Same engine here. Fan kicks on just above 200. Thermostats open right at 180. New radiator, it stays at 180. Has to be pretty warm outside to get higher. Fan only kicks on now occasionally in sumner on a hard pull. Once it kicks on, temp stays high for about 20 seconds maybe. Then it quickly drops down to 180.

 

You may not have one. He was referring to Freightliner Classic and FLD120. We don’t have actual fuses. Just the square black relays that are in your pic.

What truck do you have? Make year and model? This might help others with your questions.

 

I have a Series 60 and everything under the hood is new. My fan hardly ever comes on and it drops the temp quick when it does. Same as the others above. Comes on around 195-200. I have a scan gauge and it never has went above 207.

 

Is Your Air conditioner turned On when the fan kicks In..?

There's a Switch in the High pressure line of the A/c which also controls the Fan..!

 

I have a 1999 Freightliner fld120, I had a wiring issue after I had the oil line bust on the oil pressure gauge and it got inside the firewall and on the wires. It actually started smoking and burned one of the wires up. I got that wire unhooked and then found the ground wire from the starter to the engine was also burned up. I replace all the ground wires on the starter, but when I go to hook up the main battery wire to the starter it sparks real, bad like I’m welding, I’m not sure if it’s a bad starter or not. Thanks