Goodman/Janitrol furnace blows but no warm air
I have a goodman/janitrol AC/natural gas exterior unit. Model year 1992. This season it worked fine the first time it was on. A week later I turned it on and it doesn't blow warm air anymore. It will blow and blow but the air is never warm. Outside next to the unit, you can hear something clicking very regular. The serviceman said I need a spark igniter for 160 bucks. This on top of the 105 he charged me to come out and look at it. First, I haven't been able to find a schematic of this unit so that I can locate the igniter myself and replace it. Does anyone know what this igniter looks like, or how hard it is to replace? (I've already been to Goodman's site--no luck). Any help would be appreciated.
Thanks,
Cjh