Hoping for some help here;

Recently bought the van, blower works fine on cold, you switch it to hot, and the power on blower drops dramatically, and blows out cold air. You can hear flap in vent changing, but just blows out cold on less intensity, no heat.

Temp gauge for engine shows normal heating pattern, i just cant seem to get any of that lovely heat into the van!!!

Thanks for your time and help, any input would be greatly appreciated.