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