vacuam or electrical heater fan control problems

[sleepydan]

I recently installed a motor in a 1988 190 E ...3.2 engine used all my sensors intake and exhaust manifolds it runs good ...BUT... when you turn heater fan on med rpms change gets higher then when I turn on high really changes rpm it jumps up and lights get real bright ...have checked all grounds they are tight ...when I turn on heater to the medium and high position I can a slight noise like a vent opening under vacuam ....any body have any suggestions?

[orthotomeo]

Do you have the A/C button/ switch set to the on position?