Battery?

[250Nasty]

1995 F150, 300 6.

I have a problem, well not really a problem, just something ive noticed that ive never noticed before that I wanna head off before it becomes a problem, if indeed it really is a problem.

At night, when I have my lights on, heater blastin, and radio on, like i normally do. If i come to a stop at a light for example, my trucks battery volt or amp gauge dips a little and my lights dim slightly. Once I take off, or press the gas enough to make the rpm's increase at all, the guage goes right back to where it was when I was driving.

Is this my battery about to die? Alternator goin bad? or am I just worrying about nothing?

Thanks

[bil2303]

Possibly the alternator or the voltage regulator which is probably in the alternator. You could have it tested to check.

[Themanofallmen]

AH the ol 300 inline 6, I had over 229k miles on mine , 87 F150, before I just recently got ride of it not because it did not run, passed smog, but because of all the other little stuff that was going wrong with it. Mine did the same thing and I just put up with it. Had the Alt. tested -ok- battery -NEW- I put up with it and figured with the milage I had it brought character to the truck.

[aakmetz]

alternator, but check all battery and alternator connections too and body grounds

[Rip Wheeler]

1995 F150, 300 6.

I have a problem, well not really a problem, just something ive noticed that ive never noticed before that I wanna head off before it becomes a problem, if indeed it really is a problem.

At night, when I have my lights on, heater blastin, and radio on, like i normally do. If i come to a stop at a light for example, my trucks battery volt or amp gauge dips a little and my lights dim slightly. Once I take off, or press the gas enough to make the rpm's increase at all, the guage goes right back to where it was when I was driving.

Is this my battery about to die? Alternator goin bad? or am I just worrying about nothing?

Thanks

Normal, the charging voltage is dropping due to the lower alternator speed. And in some cases, long periods of extended idling with lots of loads on, ie heater, wipers, lights (stuff you'd find driving at night in stop and go traffic ie a traffic jamb etc) can lead to a dead battery. Now I suppose a failing battery with little or no capacity would do the same, maybe a little more, but you'd have slow cranking sometimes and other signs. You can move the idle up a smidge (is its adjustable and not all EFI rigs are)

[250Nasty]

Normal, the charging voltage is dropping due to the lower alternator speed. And in some cases, long periods of extended idling with lots of loads on, ie heater, wipers, lights (stuff you'd find driving at night in stop and go traffic ie a traffic jamb etc) can lead to a dead battery. Now I suppose a failing battery with little or no capacity would do the same, maybe a little more, but you'd have slow cranking sometimes and other signs. You can move the idle up a smidge (is its adjustable and not all EFI rigs are)

Thanks fellas

[Chickenhauler]

It's not uncommon for the lights to dim slightly at idle compared to driving RPM's on any vehicle.

My semi does it, my PU does, even the wife's new car does it.

The thing is, does the voltage drop alot, or does it stay in the safe margin?

[Farmr123]

My old pickup has done this for 10+ years, and 2 or 3 batteries. Normal for the lights to dim just a bit at idle under a big load.

[Beyond The Pale]

This is exactly what my 93 F150 I6 does. It's completely normal. The alternator is just plain wimpy. It does not generate much juice at idle and not too many amps at driving RPMs either. Add a lot of accessories and you might not be able to power them all. A common mod is to install a newer design alternator that can put out more than twice the amps. Mine crapped out a few years ago and was replaced a OEM unit before I was aware that it was a simple swap to get a lot more juice.

[87XR250R]

Does the truck idle down at all when it dims? I dunno about the I6 but on the V8 trucks of those years the idle is controlled but the IAC valve. If its gummed up and there is a big load on the alternator I would presume that its possible for it to bring it below the RPM range where the alternator works best. Just a suggestion, probalby not the problem. My lights do not dim at idle, only if i get it below 600RPM.

[kc_450_X]

I believe most cars do this. If you do a lot of idling you can change the pulley size, like an Ambulance.

To be on the safe side I would get he charging system tested. Don't want get stranded somewhere.

[kawabunga 750]

not one of my vehicles does that

85 yota

88 chevy

01 dodge

02 dodge

06 dodge

have it checked something isn't up to snuff ?

[kawabunga 750]

not one of my vehicles does that

85 yota

88 chevy

01 dodge

02 dodge

06 dodge

have it checked something isn't up to snuff ?