Extra amp draw?

I have an LQ4 with all the stock accessories. I am considering adding two ceramic heaters to the car for defrosting purposes. the truck probably uses about the same amperage draw as the stock truck the stuff came out of.

If the defrosters draw a total of 20 - 24 amps of draw when operating will this be too much for my system?

I think my alternator is a 90 amp unit. If that is the stock system. But I do not know how many amps the usual system might have to spare.

Thanks

I think the stock 2500 alt was the 105A unit for a gas motor. The Duramax may have had the 130A, but I am not sure... Since you will be running ceramic heaters, upgrade the alt. to a 145A. You will need it!

I upgraded my alt from 105 to the 13x unit. I also added a couple of ground straps to ensure proper voltage & ground.

Cool thanks for the info guys.