I am woking on an old Ruud furnace (UGDA-075C-ER) and am having quite the time with it. At the start, the blower would not come on at all; auto or on mode. In addition, the pilot (standing pilot)would light, and have a good flame, but not stay lit. One side note to the pilot, if it had been off for a while (days) it would light and stay lit for about a minute after the gas valve was turned to on. Still nothing would happen wih the rest of the system, and then after a minute or so there would be an audible "click" and the pilot would go out, not to stay lit again. After some checking with the meter, the limit switch was good, transformer bad (no 24v). Being as old as it is, my local HVAC supply hooked me up with a transformer that would work and I then wired in accordingly. Not suprisingly, the blower works fine as would be expected. The head scratcher for me now is, when lighting the pilot light it is no longer a good flame but rather a puny little flicker of a flame. I did not touch anything on the gas valve so I don't know what happened. In addition, the adjustment screw for the pilot has no effect. Anyone have any ideas?