on my 04 f350 wrench ilght came on again it has been on for a while .did a oil change and added 2 rev x for a cold start run rught light went out after oil change ran good 2 days .this am 3 mi from start light came on and gauges in dash swong over and came back truck runs fine.thanks.

 

Go to an autoparts store they will usually scan it for free

Way to many things to guess at

but does sound like your having ruff cold starts am I on track here if so then the FICM Volts needs to be checked

So check your ficm volts

https://www.ford-trucks.com/forums/8...procedure.html

here^^^^^^^^^^^^^^^

check that and code scan it you cant let this 6.0 go things can get spendy FAST with multiple failures

 

04 6.0L's don't have wrench lights. Unless I've totally missed the boat somewhere.

However, what Benny said is accurate.

Also, a dash gauge sweep indicates that the dash was reset. This is usually caused by low voltage.

 

checked batt voltage left 12,75 right 10.22 2 years old off to o riley to warrenty

 

Good Point here

Has the Battery symbol on the dash been coming on too??

 

Don't forget to replace batteries in pairs.

 

This bad battery may have taken out your ficm had to say untill you test it and I suggest that you do it soon before it starts dropping injectors too!!!

also test the Alternator make shure its ok too

This electrical stuff can take Multiple things out if one thing goes bad and you push it

When that battery light comes on its best to get right on it before you get multiple failures

 

thanks guys for the responses checked batts and charging sys volts at cragen batts ok alt ok took in to dealer was ficm and 2 glow plugs. 1 code for injector before rev x will get back tomarrow.