roof ac thumping noise heavy load problem ??
my duotherm roof ac runs normally for 5 min or so and then make a thumping noise. i opened it on the roof and the small black can like think next to the fan shakes while the interior lights dim. its obviously pulling too much power around 5 min after it starts and runs..anyone tell me why ? once it finished thumping it runs normally for 2-3 min and again makes the noise.
