02 7.3 electrical problems

[ironlemon]

Hey ive got a electrical problem on my 02 7.3. Its randomly poping the instroment pannel fuse. When it blows the bell starts going off and the doors start locking and unlocking with no gauges. Ive tried just replacing the fuse but it will blow. Right now my dads just putting in 20amp instead of the called for 10amp (fire waiting to happen i know, but its his stupidity not mine). Its popen the 20s so im at aloss of what is shorting out, is there something common? Or where do i start looking?

[NoRalPh]

putting a larger fuse in there is an idiotic move.....

Which fuse is it? What number (#45?)

[ironlemon]

it is fuse #19

Ive had it in for service 3 years ago to have a wire harness under the valve cover replaced (for the glow plugs iirc).

[ToMang07]

Sounds like the OD wire in the column is chaffed. Which fuse is it?

And remove the larger fuse, that's just

[ironlemon]

Heres some more info to help diagnose: it will always blow a fuse (#19) when you hold it down to first gear and let it shif to second manualy (auto trans). Doesnt matter if im in 4lo or 4hi, it will always blow if i shif it like that. Now if i just put it in OD with the od off it will shift all 3 just fine, but the poping of fuses seems random if i allow it to choose the gear.

[jesilvas]

Originally Posted by ToMang07

Sounds like the OD wire in the column is chaffed.

Originally Posted by ironlemon

Heres some more info to help diagnose: it will always blow a fuse (#19) when you hold it down to first gear and let it shif to second manualy (auto trans). Doesnt matter if im in 4lo or 4hi, it will always blow if i shif it like that. Now if i just put it in OD with the od off it will shift all 3 just fine, but the poping of fuses seems random if i allow it to choose the gear.

See above quote. It would make sense.

Auxiliary Powertrain Control Module
(APCM) (Diesel only), Instrument Cluster,
GEM Module, Overdrive Cancel Switch, Idle
Validation Switch (Diesel only), Overhead
Console, Diesel PCM via Clutch

That's what #19 handles. It's a 10A.

[ironlemon]

Ok i just did more testing. Setting in the shed, idling, holding it in 1st then allowing it to go to 2nd, without actually moving just allowing it to have second, it will blow fuses all day long. 2nd to 3rd wont bother its just 1st to 2nd.

So based on what that fuse controls its probably related to the apcm. The od wire could be it but it doesnt apply if the truck is not physically moving. Pressing the od cancel button doesnt make a diff while allowing it to have 2nd gear while setting still.

[ToMang07]

Have you even checked the column wires yet?

There is also a wiring harness on the drivers side valve cover that can chafe on the VC. It's right under the Intake. (10mm socket to remove.)

[ironlemon]

Ive looked with the pop of lid off yes, with my head light on. I can see anything with moving anthing around. I will check the valve cover harness.

[NoRalPh]

Originally Posted by ironlemon

Ive looked with the pop of lid off yes, with my head light on..

Not sure what all that means,,, but, you need to remove the column covers (you'll have to pull the key cyl to get the top one off) and lift the two little wires at the base of the shift lever (that go to the OD sw) and see if they're not chafed through underneath (VERY COMMON reason to blow #19).