Background: About 2 mo ago, I would be driving and the voltage as displayed on my Edge Evolution monitor would go from approx 12v to 8.9v. Dash lights would flicker, radio lights dimmed, head lights would dim, etc. When it shut off, it wouldn't start. After a good charge I was up and going again. Well, I finally tested the batteries and the single alternator. All were bad. Replaced them all.

Current Issue: Before I fixed the alt/battery issue, all my gauges and power windows quit working. After I fixed the alt/battery issue, I'm running at 13.5v, but I still have an outage. Specifically, I have no power windows, no interior dome lights (none of them work), no running board lights, the radio clock works but radio won't power on, the headlights/running lights will only work in the manual on position (auto on does not work), no analog gauges work in the instrument cluster (no tach, speedo, fuel, H2O temp, tranny temp, oil press). Additionally on the instrument cluster, the warning lights for the E-brake, door open, and "check gage" are always on but dimmer than normal. Furthermore, the glow plug light does not come on at start-up (but I'm not having issues starting).

The truck runs like it should, and everything else electrical not mentioned works just like it should. To be redundant, the turn signal indicators on the instrument cluster work (as do the turn signals themselves), the cruise works and the light comes on, the ABS light comes on and then goes out at start-up, heater works, door locks, etc.

Finally, there are no blown fuses in the fuse panel by the driver's knee. I don't have the codes with me, but the DTCs were something about a fuel circuit fault and loss of instrument cluster comm. I reset the DTCs after the new alternator and I still get the fuel circuit fault code.
Are you experts thinking the fuel circuit DTC is the cause or an effect? I'm thinking I fried a voltage regulator or something, but I don't know where to start. Is there something that all these symptoms has in common, bearing in mind that some things do work?

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- Fish
2003 Ford Excursion, 6.0 PSD, 131,000 miles

 

Try these ideas:

https://www.ford-trucks.com/forums/9...on-issues.html

 

the fuel circuit a fault is normally caused by the fuel pump. but with all the other stuff you have It may not be the case. However that is a 2 wire circuit and may be the easyist to chase down. I would try to get a copy of the wiring diagram and see what they all have in common to start.

 

Sounds like the PCM is still running in limp mode.

 

In the AM, I'll try the reboot... disconnnect the batteries and turn on the headlights for 20 min. I'll let you know how that goes. Too bad it's about 10 deg outside!!!

 

limp home has nothing to do with it limp home mode is a reduced power function.

 

IT WORKED! Did the PCM reset trick and all is well!

Thanks gearloose1! Give me your mailing address and I'll send you some venison.

 

LOL.....


Thanks, but that will not be necessary.

Just enjoy yourself on this site.

 

I know this is way old, but it saved the day for me so I wanted to acknowledge it and maybe bring to the forefront for those with these now 15-20 year old trucks. I very seldom drive the 2003 6.0 in the winter, but try to keep the batteries charged through the winter just cause. With our weather warming up I decided to make a 40 mile run just because. When I opened the door and there was no dome light I knew something was amiss. She fired right up, but no gauges, radio, dome lights or windows. Checked all the fuses, and they were good. Came inside and this was the first search hit I got. Disconnected the batteries for 30 minutes with the headlight switch on. Hooked the batteries, and knew when I opened the door that we had a winner! Thanks again for the straight skinny.

As an interesting aside, all my radio presets were still in the radio?