Another issue... my battery light on my dash comes on intermittently....

Last winter (2013-14) I noticed that my in dash battery light came on intermittently. It would come on upon a cold start in the morning and stayed on until what I assume is the glow plugs turning off. I say this because although I dont have a dedicated indicator light for my glow plug relay, I have my dimmer switch for my A-pillar gauges turned low and they have acted as a glow plug indicator (or so I assume). What I mean is that when starting the truck, my A-pillar gauge lights are not illuminated. But after about 2 minutes the gauge lights come on (approx the time for glow plug relay to kick out) also headlights get brighter at same time if dark outside which is another reason why i thought glow plug relay. This is how things have operated since installation of the pillar gauges several yrs back now.

Ok, back to issue, starting last year the battery light would come on at start, pillar lights dim and then intermittently for upwards of 20-30 minutes after starting the battery light comes on and the pillar gauges dim. This happens anywhere from a few seconds to upwards of a minute or so at a time. But once the engine and everything warms up the issue went away. This occurred all winter long. Once spring time arrived and temps warmed up the issue went away other than at initial startup.

Now coming up to this past winter (2014-15) after the first cool spell it started again. I assumed that my batteries needed changing (due to issue in colder temps) as it had been a few years since replacement. Replaced with new batteries, issue still remains. This same sequence has repeated itself daily throughout this past winter season. With one exception being that occasionally even after the engine has warmed up 30 min+ the issue returns. Battery light comes on and pillar gauges dim.

Now that we are coming into spring time again and temps here in south La are rising into the 70s-80s at this time, the issue has not gone away like it did last year with the warmer temps. My thoughts are drifting towards the glow plug relay finally going out, although I am not familiar with the symptoms of the relay failure. I purchased a Stancor relay yrs ago but never replaced it because of the "if it aint broke dont fix it" mentality. I would switch it out now but want to know that this could be the issue or should i look elsewhere? If I recall, isnt there a sensor that tells the glow plug relay to turn on when things are cold? Could it be a sensor going out that needs replacing?

Again, this is just a light issue with the in dash battery light coming on, but there is a voltage drop to cause the pillar gauge lights to dim. All i have is the factory volt meter, it doesnt show much if anything while this is occurring, and the factory dash lights do not dim, only the pillar gauge lights because I have the potentiometer is turned down on purpose to have brightness of pillar gauges not over power the oem dash. Otherwise the truck runs fine, no issues there, just an annoying light and an apparent voltage drop. Wondering what course of action to take before the culprit does raise its head and leave me somewhere (I hate learning those kind of lessons). Again, any and all help is appreciated.

 

Every time my battery light has come on it has been an indicator of a bad alternator, which fits many of your symptoms.

 

What is a good upgrade for alternator? Im not going back the parts house route (did that every yr for 3-4 yrs, lifetime warranty crap...), and the one that is on there now was rebuilt by a local shop about 3 yrs ago. Is there a good aftermarket one out there that is bigger/better?

 

If it were me I'd find a used, known original unit and have a quality shop rebuild IT.

I am surprised you only got 3-4 years out of a rebuilt original before.

I had mine done from my L99 about 6 months ago @130k miles, the shop said it would go that amount of time and miles again easy.

 

I went with a new NAPA unit for a 2005...140 amps. $300. Minor filing of the bracket required.

 

My local rebuilder leaves something to be desired. I've got the 6 leaker alternator also. Higher amps. Just clock the case and touch a grinder to the bracket or add a couple of washers and you're good to go.

I did go new, not rebuilt. https://www.ford-trucks.com/forums/1...lternator.html