Alternator

[BIG JOE]

main reason i started thinking about this , is the battery light flickered on and off other day at idle... but once i drove it went away and didnt come back.. im guessing im nearing time.. also could a alternator going out hurt my ficm? and do you just tighten belt to make up difference in smaller pulley? thanks guys

I had the same symptoms.. Flickering batt light.. flickering became On then Off, then, more on than off.

Today's engines are purdy sensitive to proper voltage and amps.. so I would say Yes.. an Alternator, on it's way out.. could cause performance issues, and could/would do damage to sensitive components, at some point.

I had noticed my 7.3 idling a bit rough at times, and seemed to lack it's normal power at times too. I thought it was the "Winter Blend" fuel.. ALL that went away, when I R&R'd the Alternator.

The belt tentioner took up whatever slack was created... by the pulley diameter dif.

Joe

 

[Jetpilot1]

Matt

Something to keep in mind is that when a battery loses a cell, it is a constant load on the alternator - alot of alternators die because the battery(s) were weak. When you replace the alternator - make sure the batteries are solid.

 

[nascar_fan28]

thanks guys for the help.. i put new motorcraft batteries in december. im gonna have a local shop rebuild mine, mainly cuz i like to give them work, and i can get it done today.

 

[Matt24601]

My battery light came on this morning. Now I just replaced my alternator a few weeks ago with a new 160amp unit. I am wondering if it is one of the batteries. I took it by Autozone this morning to get the batteries tested. While still hooked up in the engine the guy said both batteries tested fine. With the engine idling at 1500rpm his scanner said that the charging system was only putting out 11.6 volts.

A few concerns: If the batteries were still connected to each other while in the engine when they were tested, how could you test just one of them? They are wired together so by hooking up your leads to one, aren't you also indirectly hooking up to the other one? Should I remove both batteries and have them bench tested again? If the batteries are indeed fine, and we assume that the new alternator is fine, what else is there in the charging system that could be going wrong? Any solenoids or anything that I might look into?

 

[DaveBen]

Your alternator is not putting out. Get anew one and don't go cheap. This happens with cheap auto parts. They die quickly.

Dave

 

[Matt24601]

Alternator is not cheap. As noted in the previous posts in this thread, I bought the 160amp 6G replacement unit from Alternatorparts.com. That was less than 4 weeks ago. I've got to assume something else is going wrong here. I took both batteries out and took them up to Autozone again this afternoon, both tested fine.

 

[Jetpilot1]

It is a good quality alternator - way better than stock, but it is not putting out for whatever reason - time to check out the alternator.

 

[Jetpilot1]

Did you get the heavy duty internal rectifier? A heavy duty alternator is no good with normal duty rectifier, cause that's what usually blows in the alternator.

Also - re-check the connections you made to the alternator.

 

[Desertstroker]

I have an 04 f250. Battery light is flickering. How do I get the belt loose enough to get over alternator pulley to change alternator. Thanks

 

[BIG JOE]

I have an 04 f250. Battery light is flickering. How do I get the belt loose enough to get over alternator pulley to change alternator. Thanks

Under the hood, usually on the radiator support there's a label/sticker showing the proper routing of the Serp. belt. It also shows the position of the [Tensioner Pulley].. With a 3/8" breaker bar inserted in the socket type hole.. pull on the Tensioner, relieving the tension.. slide the belt off. do the same to put it back on.

Joe