Alternator Normal ??

[Norquist]

I just noticed that when I start my truck and it's cold, meaning having to wait to start it... the alternator gauge sits at about 12 volts for approximately 20-30 seconds then climbs to it's normal operating range.

Now if it's warm,, not sitting long, it goes right up to normal range.

Is this normal? Seems like there is some sort of time delay restricting output when it's cold.

[IndigoDually]

That's normal. What you are seeing is the intake air heater. It is on for around 30 seconds or so depending upon the ambient air temperature. When it is running it draws a good deal of amperage which is why the volt gauge is a little slow to recover.

John

[copperhead]

That answers that, I didn't know I had and intake air heater, did notice my voltmeter running low for a short while after startup.