ENC on bussman fuse holder

[greezykid]

I am blowing 3 -7.5 fuses on 2000 diesel gulfsteam sun sport .Bussman fuse holder identifies as ENC 1,ENC 2 and ENC 3.They have my engine and transmission shut down.Transmission not showing codes and is communicating with shifter.John at transmission instruments does not think it is tranny ecu. I'm trying to find out if they go to the Cummins ecu.

[Skip426]

The Freightliner wiring schematic I have for my chassis , also covers Cummins engines and identifies 5 fuses feeding the Cummins ECM three 7.5 and two 10 amp. But doesn't give a location in the fuse block.
Disconnect the Cummins ECM on the side of the engine and try installing fuses.

EDIT: Could you add the chassis manufacturer and Cummins engine size to your post.

[greezykid]

Thanks Skip, it's a Spartan chassis with 5.9 275hp.Yesterday I noticed the gauges also jumped around and shut off when turning key on making me think it was the ecu.They put it in a place that will really make me talk to myself getting it out.You just saved me that call for a mobile mechanic.I was thinking you might read my post and be of some help. Any suggestions on where to get one to replace it or does anybody rebuild them. Thanks again for the help.

[Skip426]

I'll dig around and see if I can narrow down , what each fuse is for ; as far as ECM outputs; but blowing all 3 doesn't sound good. I'm thinking internal issues.
Cummins is pretty protective of their electronics , so I don't know if any one but Cummins will be able to supply a replacement .
Maybe a Google search.

[Skip426]

OK , a second thought , I always have them . VP-44 injector pump internal electronics .
Disconnect the wiring from the ECM and install fuses , to test the wiring from the fuses, to the ECM.
Then disconnect the wiring from the injector pump and reconnect the ECM.
Figure 5 in this pdf. shows some of the 7.5 amp fuses feed the VP-44.

[greezykid]

I pulled ecm and all fuses stay active ,ordered rebuilt from cummins and will install this week.Original was titled for utility and cummins suggested to get one titled for motorhome,sounds logical so that's what I got.Thanks again for the help.

[Skip426]

Originally Posted by greezykid

I pulled ecm and all fuses stay active ,ordered rebuilt from cummins and will install this week.Original was titled for utility and cummins suggested to get one titled for motorhome,sounds logical so that's what I got.Thanks again for the help.

Let us know how that goes ; I've still got a funny feeling about the VP-44 electronics.
At the shop we had a tool that allowed us to by-pass the ECM and feed power direct to the VP-44 for start up and idle, I can only remember using it once;( in 8 years of dealing with the VP-44) , but it would sure be handy in your case.

[Bob_C]

It also bypassed the crank sensor....

[greezykid]

Got new ecm installed and I called cummins to check all wiring before installing.He checked everything ,said no shorts so I presumed it was bad ecm.Engine fired up and ran good,he turned it off and started it 2 or 3 times,then it blew all the fuses again.Mechanic gave up and went back to shop to look for more imformation.It is not a dead short it's something warming up and then shorting it out.He said he would be back so I'm still out of commission.Also probably did not need new ecm,

[greezykid]

Cummins ran 3 new hot lines from battery to ecm and everything is working.Short was on ground side and have not found anything else it effected.

[Skip426]

I hope they got it fixed for you , because that description " short on the ground side " makes absolutely no sense to me.

Short to ground, hidden in the wiring harness , I would believe.

[greezykid]

I believe you are right the original just blew fuses,he bypassed it and hooked 3 fused hots off battery. Everything is working so far.

[YC1]

https://www.amazon.com/ELEGIANT-Mult...=signal+tracer

Place the signal on the cold side of the fuse holder. That is, find which side is hot all the time and do not use that side. Inject the tone into the side that feeds the whatever.

These signal tracers are so cheap now that everyone that is a weekender should get one and experiment with them.

I'm a 40 year exeprienced tech and chasing these wires and electrical circuits can be near impossible. Schematics are lousy.

If you are in a hurry, Lowes and Home Depot have signal injectors. Granted, these tools are cheaply made and do not compare to the hundreds of dollars it cost to buy commercial quality stuff but they get me by fine now that I am retired.

[greezykid]

I tried that for 8 hrs before I called cummins.