I have a coleman central electric furnace model#3500-816.the airconditioner and blower motor are workinking just fine,but the heater and blower motor won't come on when it's in the heat position.I checked the thermostat it tested OK,there is voltage going into the sequencer, but I'm not getting any voltage coming out of sequencer.could that be the problem(sequencer)?and if so how can I tell with is the right part# to order?

Mark the wires as to where they connect,or take a closeup photo,, then remove it and take with you to parts house

You can find your part# here #3115-357 (mobilehomerepair.com/ColemanElec.html) but any universal will work in its place. The voltage you need to check for is 24v lower part of the sequencer.