Nick Comstock
Nick Comstock MegaDork
12/3/22 8:13 p.m.

A guy at work is having issues on his truck. Codes are all related to sensors either having low or high voltages. Mainly MAF and air intake sensors but there were a lot of codes I don't remember right now. 

Anyway I found a blown fuse number 43, which the description only indicates as ENG. 

Does anyone know if the ENG fuse powers those sensors?

TJL (Forum Supporter)
TJL (Forum Supporter) Dork
12/4/22 7:26 a.m.

Sounds like an issue with grounding or power is freaking things out. 

OHSCrifle
OHSCrifle GRM+ Memberand UltraDork
12/4/22 8:58 a.m.

Even though you are in FL, I would proceed directly to the ground strap that was culprit in this Eric O video  

https://youtu.be/8CFZcO4NDhI

..i also wish I knew how to embed video using an iPhone. 

Nick Comstock
Nick Comstock MegaDork
12/4/22 1:49 p.m.

Yeah I told him he needs to Check his grounds for sure.  I was trying to figure out what that fuse powers.  So maybe I can figure out why it blew in the first place.  But I can't find what eng means anywhere. 

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
12/4/22 10:03 p.m.

Find out what it powers, which is probably all related to the codes you got.  Knowing what they are is absolutely essential.

You'll find either a shorted component or a chafed wiring harness, probably where it passes under or over something.  If you replace the fuse and it blows right away, GOOD!  That means you can find the problem.  Stick two spade terminals on a headlight bulb, or a washer fluid pump so you can hear it buzzing (a horn works too but is really, really obnoxious), plug THAT in to the fuse socket so it will become the load in the circuit.  Then wiggle the loom until it goes out.  If it doesn't go out, unplug things on that circuit until it does.

No bets that it's a pink wire... GM loved to make ALL ignition switched power wires pink, for a forest of pink wires in the loom.

OHSCrifle
OHSCrifle GRM+ Memberand UltraDork
12/5/22 7:22 a.m.

Related: where can I find model specific wiring diagrams? Do shops use some kind of subscription?

Ranger50
Ranger50 MegaDork
12/5/22 8:31 a.m.

In reply to OHSCrifle :

Alldata or Mitchell 

Nick Comstock
Nick Comstock MegaDork
12/5/22 6:31 p.m.

So he says replacing the fuse fixed it. The thing is I put a 10A in and it was supposed to be a 15A. He said the 10A didn't blow.  

Ranger50
Ranger50 MegaDork
12/5/22 6:43 p.m.

In reply to Nick Comstock :

Not yet.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
12/5/22 6:49 p.m.

So probably a chafed wire.  When a component decides to go to zero ohms, it tends to stay that way.

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