Battery Light and FICM

[jmisbpd]

Hey again guys, I posted a little earlier about a possible FICM problem, which I was able to confirm. Now prior to experiencing all of these issues with the way the truck was running (and now not running), I would have an intermittent battery light pop up on the dash. It would go on and off, I did test the alt and batteries a few months back and dont remember the numbers exactly but I know I never broke 14v at the alt or the batteries with the truck running, I didn't think that was too bad but now I'm thinking that may have caused the FICM to take a crap on me.

I did not test the voltage at the alternator or batteries while I was having these rough running, hard start and no start issues, but I'm assuming that if there was a problem with charging it only got worse and eventually led me to where I am today; with no truck!

Question is here, I bought a refurbed FICM; would it be a good idea to replace the alternator and batteries and check all grounds and connections prior to the FICM coming in and installing it? I'm thinking if the batteries were bad and caused this issue to begin with I'll only be going through it again very soon if I don't.

2003 F-250 6.0

[10secondC]

I'd load test both batteries after disconnecting them. If either tests bad replace both and, if it were me I'd replace the alternator as well. I just went through this and can tell you a bad battery will take out both the alternator and the FICM.

[jmisbpd]

Yeah, I'm kicking myself in the A$$ now for not just taking care of it sooner. I asked another buddy of mine with the same model and year truck and he said his batt light was doing the same thing and has had no issues, and he's a pretty knowlegable guy, so I chalked it up to just a common problem.. Turns out my truck was trying to tell me something! Just killing me, 500 on a new FICM and now another few hundred on batteries and an alternator. Thanks for the reply man!

[10secondC]

Send the FICM out to FICMrepair.com. Couple hundred and you'll get it back all fixed with a 1 year warranty.

[jmisbpd]

I actually got one from northern auto parts its a refurb preprogrammed for 483 but I mail mine back and they give 200 for a core. Keeping my fingers crossed!

[Paul2000]

If they are 5 years old or so it might be money well spent to just replace them to be safe. Batteries don't usually last more than about 5 years and considering this particular engine having a huge financial penalty of the battery dieing under use, I will be replacing mine every 5 years weather it is showing signs or not. If they aren't completely bad it is not a waste because they are guaranteed to go out a short time later anyway and I don't have the compounded worry of waiting for them to go out and taking expensive parts with them.

Also, alternators aren't meant to charge batteries from dead, it takes a lot of current to charge a dead battery. Alternators are meant to maintain a charge on a battery. You can actually kill an alternator by trying to charge dead batteries with it. You should charge new batteries with a battery charger before using them. On our trucks you can install them and charge both at the same time by just hooking up to one battery since they are connected in parallel.

I have jumped dead batteries with another vehicle in the past and driven off, but I would not risk that with today's complex and expensive systems. It would be a gamble in today's tech world.

[jmisbpd]

Thanks paul I bought the truck last July and I have no idea how old the batteries old which is probably not a good thing. The alt looks like a reman and fairly new but ill be replacing it all to play it safe. Probably a good idea