Alright, well to start off, I'm a newbie to the site, not the truck. I DID read the newbie stickys.

Truck: 2005 F-350 DRW 6.0. ARP Studs, aftermarker oil cooler, EGR delete, 4in straight pipe, CAI, SCT by Innovative. 170k on the clock. Auto.

Problem(s): A couple weeks ago I noticed that I lost power to all my gauges, radio, and windows. It cut out for about 20 sec, or so then came back on. I was on the highway. Everything else worked (headlights, HVAC, truck ran fine, etc). A few google searches and phone calls to my diesel mech. buddy later, I narrowed it down to a failed GEM module, or bad cluster.

Now, this might just be coincidence, but today, My fuel gauge read zero from half a tank (no, I didn't leak it out) and it ran fine for a 5 min drive. Drove it back a short while later, and it bogged out, and bucked the whole way back if I gave it any more than 10% throttle. My question is: Is this related to the electrical issues from either the GEM or cluster going kaput? Or is it mere coincidence that either my fuel pump, or sending unit **** the bed? And is there more testing I can do to determine which one(sending unit, or pump) to replace. Same goes for the cluster / GEM.

Thanks all!

 

Use a voltage tester to test the batts while running, it should be around 14.2-14.4 volts. if it is much lower then that then it is probably the alternator. most auto parts stores will load test your batteries for free.

 

Just hit it with the sct. Reads 13v flat at Idle. 1500 rpm yields 13.4v. Gonna pull the Alt tmrw and have the parts house test it.

 

Yeah, that voltage isn't good enough to keep the batteries charged and run the truck properly, these things need a lot of juice while running.

 

I pulled the Alt yesterday and had it tested, and it came back good. I re-installed it and hit it with a real battery tester, and it gave the right voltage. Also, in disconnecting the batteries, something must have reset itself because The fuel gauge read correctly, and I had no issues driving the truck. Cluster is still toast, however...