When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Question for y'all, I've got an 03 with a late 04 engine. Been having battery issues but my jump pack has been getting it going no problem until today. Now it won't stay running after its going. What should I look at first besides batteries? I'll be picking up a set tomorrow.
If you've been trying to start it with low voltage batteries, I'd be checking the FICM voltages. How to do it is listed up at top of the 6.0 main page under READ FIRST Tech Folder.
Question for y'all, I've got an 03 with a late 04 engine. Been having battery issues but my jump pack has been getting it going no problem until today. Now it won't stay running after its going. What should I look at first besides batteries? I'll be picking up a set tomorrow.
Low voltage almost guarantees a bad FICM along with several other issues. These trucks need proper cranking voltage.
Put in some agm batteries and logged the starting voltages on them, 12.68 and 12.8. Started it up, runs great so sounds like ficm survived... Monitored the voltages for 10 minutes or so and they dropped very slowly. Looks like I'm going to be replacing my alternator now. What's a good upgrade from the oem one?
The 140amp alternator is a great cheap upgrade to the 110amp that came with most trucks. Can get it at most auto parts stores
Called the parts store, he had a footnote in his system saying the 140amp alternator was only for use with a dual alt setup. Mine is a single. Is that true? If so why?
It should mount right up. Just make sure the electrical connection is in the same spot as the one you’re replacing. There is a version where the rear is clocked differently with the connector on the other side
Most trucks came with 110 and dual alternator trucks had the 140, so maybe that’s why they list it that way
So I'm not sure, but I might be crying wolf with the alternator. I'm running the truck and the batteries are hanging out at a consistent 12.45-12.5 volts. I thought they were supposed to get to 14.4 ish volts though.
What is the alternator output voltage supposed to be? Mines logging 12.5 ish
With new batteries and voltages that low, I would suspect the alternator (assuming all battery wiring connections are good - including the grounding points). Any parts store can test the alternator.
With new batteries and voltages that low, I would suspect the alternator (assuming all battery wiring connections are good - including the grounding points). Any parts store can test the alternator.
You mean the alt output voltage? I'm assuming 12.5v is low, 14.4v is where the batteries are supposed to sit fully charged right?
Left it running another 10, went out and batteries are over 13 now. Alt is working just seems like it's slow and weak. Shouldn't it charge to full within minutes?
Granted I have a 270amp alternator, but it’s at 14.4 within seconds after starting. I’d replace that alternator before it damages something. But that’s me. 😊
Granted I have a 270amp alternator, but it’s at 14.4 within seconds after starting. I’d replace that alternator before it damages something. But that’s me. 😊
Sure that makes sense. I'm thinking about getting this one from fullforcediesel, it's about $120.more than a 140amp tho
Should be good, just check with them to make sure it’s ok for the AGM batteries you just bought. I remember when I bought mine from FICMRepair there was something about the voltage regulator to make sure it was compatible with AGM’s
