FG reading to low?

I brewed a blonde ale and used wpl001 for the first time. I took a couple of days to start but then did real well. As per the recipe I set the OG at 1.063 and the final was supposed to be 1.016. After the activity died down I checked it again and it shows 1.003 I lost the little temp chart that came with the hydrometer so maybe that is the problem? I racked it to the secondary @64 degrees.

WOW!

My gues is that you mashed too low.

What was your recipe?

Mashing low and long would lower it, but there may be other contributing factors as well. What does your hydrometer read in plain water? Every 10 degrees cooler will make it read about 1 point higher. (near room temperature) WLP001 is 73%-80% attenuation and you're at 95%. Is there any simple sugar in your recipe?

I am still doing a partial mash until my beer stand is finished so I dont think it was the mash.
Recipe:
6.25# light dme
2# dom special pale
.625 vienna
2 oz hallertauer hersbrucker

Simple but makes a real nice beer.