Been awhile. Always know where to go when I really need assistance.
1997, 7.3, E4OD, 887K miles, E-Fuel
so over the past month I had the BATT light flicker every once in awhile. Batteries are 4 years old so I’ve been holding on for as long as I could. Heading home from work yesterday the BATT light turned solid. And at the same time the truck started to sputter like I had a real dirty fuel filter. Barely make it home.
so for starters today I changed the alternator and both batteries. Same results. Solid red BATT light and the needle wouldn’t get past the “N” on the “normal” voltage meter. Still had the sputter. Any insight would be great.
thx

 

I had a flickering batt light myself recently. Went through 3 reman alternators before found one that worked properly. 2 undercharged and one overcharged. The voltage regulators are junk on most of the remans, doesn't seem to matter whose sticker is on the side either.

 

your friend

 

figures! ha.
so would lack of voltage mess with the engine running rough?
thx

 

I am all about popping new brushes on an old Motorcraft VR too. Runs about $7.

 

Lack of voltage could cause issues. Namely the slow death of your batteries. Things are used to getting 13-14 volts with a good alternator, getting maybe 10 with just batteries.

 

Stock engine with mechanical fuel pump doesn't need much current to run, once started. It will happily run a long time on batteries, past the point where headlights noticeably dim and the batteries don't have enough left to start the engine. I inadvertently ran that experiment.

In your case, fuel is dependent on current and voltage, so how the fuel pump handles low voltage affects how the engine runs. You may be getting low fuel pressure and volume before the PCM, IDM, and injectors start having problems from inadequate current and voltage.

You probably should check your battery connections, cables, and main grounds for corrosion / breaks / loose connections. Problems there could be choking off otherwise good alternator and batteries. Also check the wire harness to the top of the alternator. Its location makes it vulnerable to damage from tools, parts, and people laying on it during maintenance. You might have broken wires just outside the connector.

 

thanks. So I swapped out the alternator and that’s all that it was. The sputtering was from a broken wire on my efuel pump. Back in action!
thanks a bunch

 

Multiple problems combining. Bad original alternator, bad replacement alternator, bad wiring to fuel pump. Glad that you found them.

Diagnosis can be, um, "fun", and often requires checking performance information with some instruments. Fuel pressure gage, test light, multimeter are basics. Then figuring out what the info tells you about your vehicle, and what it does not tell you. "What I know, and what I don't know". Lots of guys miss the last part.