location of ecm fuse(s)? im going crazy!please help


New Member
yes my first post on this forum is a cry for help as i cant find the ecm fuse or fuses on my 97 peterbilt 379 with a 3406e cat.

everyone says they come out of the battery box or in that area all i have coming out of my battery box is postive and negative going to starter.
ive looked behind dash,disassebled kick panels,looked behind battery box,pulled out just about all wires and cables in the area of the starter and where the battery leads goto.

then there some places which say that the fuses are located along the firewall above the engine and all i have there is a blank space.

there were a set of fuses i think 4 or 5 behind one of the dash panels and all of the fuses where good on that block as well.

whats the deal where are the fuses located on my pete.
the fuses located behind the driver side kick panel are all good and none of the breakers are popped out, my fuse cover doesnt have the label so i dont know if the ecm fuse is on that inside fuse panel. everyone tells me its outside the cab by the batterys.


New Member
my problem is the truck isnt turning on its kicking over it has fuel and no air just isnt starting, i used ether but it only stay on with it and hardly at that, as if there is no computer signal telling the engine to run. the check engine light comes on for like 4-5 seconds while the ignition cylces and then turns off like normal but then nothing it just turns over with no change, all other lights on dash turn on as well,low air buzzer to, rpm guage is also moving when engine is turning over as well. any help would be great on this as i have no clue as to why i am having this issue.

i started it early in the morning left her running for like 15 mins then turned off and turned back on again to take her for a drive and she turned on rough then just sputtered off.


Staff member
if it is trying to start with ether my first thought is I would suspect a bad fuel pump. first thing though check for a clogged fuel filter, then crack a fuel line past the filters and pump and turn the switch on and see if you have fuel flow, I once had a collapsed fuel line that drove me nuts tracking down until I disconnected it and put a hose on it and put the end in a 5 gal can of fuel ans started it up, it ran sweet that way, replaced the line from the tanks to the pump and away I went

Racer X 69

^^^ What he said ^^^

Sounds like you aren't getting fuel. If there was a problem with power getting to the ECM the Check Engine Light would not be blinking.

Figure out why you aren't getting fuel.

It could be the transfer pump.

And you should be able to put the ECM into diagnostic mode, which will start the CEL blinking. It is kind of like morse code. One blink and a pause means the number 1. Two blinks and a pause means number 2. And so on.

If the truck has an electric transfer pump, and if it is bad, there will be a code for that.

Oh, and the fuses for the ECM should be inline with large (like #10 gage) red wires that are connected directly to the batteries. They might not be right at the battery connection, but they shouldn't be too far away from it. Start with where the wires are connected to the positive battery terminal and follow them. You will find them, they are there.

Gin 3408

New Member
They not near batteries in a 97 379. I can’t find the battery to ecm fuse in my 97 either. Peterbilt can’t tell me where it at either. I put a new wire with inline fuse from battery and spliced into ecm where battery wire was supposed to be. If someone knows where it is let me know. Don’t tell me battery box or somewhere near.

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