Engine/Transmission (1998.5 - 2002) Upgraded Alternator: How do I know if I need one?

[PCarbonaro]

I've recently added many LEDs, and will be adding off-road lights. With all lights running, should I look at my voltmeter to see if my alternator is up to snuff?

 

[cumminsday]

That is usually a good indication. If with all the lights on the voltmeter does not drop below normal or less than 12 volts, the alternator should be adequate. Also, something to remember about LED's is that they use very little power to operate, these should very minimal effect on the system.

 

[WestTN]

You need to find out how much power the lights consume. It is possible to overload the alternator even though the voltage remains where it should be. The alternator amperage rating is not valid for continuous service. It is a peak rating. Continuous draw at even half of the rating may shorten the life greatly due to overheating. Anything much over 25% of the rated load can lead to trouble. Our alternators put out a lot of power in the winter to recharge 2 batteries and to supply the intake heaters, fuel heater, cab heater, computer and lift pump, and the usual load of lights. Of course, in that circumstance, they have very cold air to help cool them.

 

[Supermod56]

That's the main reason I had LED's put on my new 28ft trailer, because they pull hardly any juice, and the voltmeter doesn't drop at all, and no heat issues with the alternator, but keep an eye on it.

Tom

 

[PCarbonaro]

Thanks guys. There are a lot of incandescent lights as well as LEDs (I'll post up new pics when I get the truck back). I was thinking the off-road lights would put me over the edge. Again, I just didn't know what to look for with an overtaxed alternator. I'll probably go for a heavier duty one anyway soon...