Hi, I'm working on a 2002 1500 that was blowing ECM's. Added fuses to the main B+ and ASD Sense input as described in other posts. Also replaced the generator due to bad bearings.
Now what's happening is the truck will run, and to prevent blowing ECM's, I have a 3A fuse in the ASD sense wire going to the ECM. The fuse randomly blows now. Sometimes the truck will run for a few minutes and sometimes for 10-15 minutes. I verified the ASD relay is working correctly.

Question is, if this is really a "sense" input, how much current should be flowing in this circuit?
Is 3A too small perhaps?
I really don't want to increase this fuse unless I know for sure how much current is supposed to flow here since that seems to be why the ECM was originally blowing.

 

are there any codes with this? if you are adding a fuse to an otherwise non fuse circuit, yes there is something really wrong. Are their certain circuits or pins you are working on? Wire color, location and all? The more info you can give the better it is for anyone to help you. I have a factory manual I might be able to find more out but need more info. Others have them also, some digital..

I say this as I remember being 16 and putting a larger fuse in the place of a lower fuse. 3 weeks and $650.00 later, multiple trips back to a company to fix the wiring harness as the larger fuse let a grounded wire melt the loom. This could actually be what is taking place right now, you could have multiple circuits that have shorted out. Check your entire wire loom.

 

It's the asd sense circuit dg/or wire on connector c of the ecm. I put the fuse on this input so the ecm would stop blowing up. I would not expect current to flow in a "sense" input so pulling over 3a is trouble in my mind, unless that input has another use in the ecm.