Furnace Troubleshooting and the "Know Where Man"

(This picture is not my panel thankfully)

I was working on finishing may basement last Weekend. I was improving the wall insulation around the electrical panel, pushing insulation in behind the wires on the panel board.
Shortly after my wife called downstairs and told me the furnace fan would not come on.
I never connected it since i had not tripped any breakers.

Well, then began the furnace troubleshooting. I called a young friend with some training on HVAC and we looked it over.
- No lights on the furnace.
- Open the furnace panels.
- Check the power: 110V coming in.(So we thought.)
- Check power going to the furnace panel safety switch: 110V
- switch to 24VAC transformer 110V coming in Zero VAC coming out: AH HA! Bad Transformer we thought
- Wrote down the part number.
- My wife called a local Electrical supplier who could get the part.
- Picked it up next day for $50.
- Put it in .... SAME PROBLEM! What? thats not it? where did we go wrong?

Dumbfounded and given up now on self repair we called in a professional Furnace man.
first thing he checked (of course) was the power coming in ...
"Only 96V coming in " he declared. "REALLY ?" I sceptically replied. Wondering "is he checking this right?"
Immediately he went back to the on off switch and opened it up. "still only 96V."
Over to the Electrical panel he removed the panel cover. here he found a loose (black) wire on the breaker. Rechecked it: still only 96V. Poked around in the rats nest of wires the builder had installed.
Here he found an even looser (white) Neutral wire (Slightly discolored from heat).
Tightened the wire and presto! furnace lit up.

We wrote out a check for $125 to the furnace man while my Wife scolded me for not finding it.

Now our error : was how we checked the power coming in. We tested the AC line in from the black wire to ground! (for ground we used the furnace body).
We should have checked across the Black and the White wire! we would have seen the lower voltage.
Loose wires on a panel are bad thing. I'm glad we found this!
---

As for my wife complaining about paying $125 for a guy to tighten 2 screws it reminds me of this story about Henry Ford's "Know Where man" ...

http://answers.google.com/answers/threadview?id=183998
http://www.snopes.com/business/genius/where.asp

"Nikola Tesla visited Henry Ford at his factory, which was having some
kind of difficulty. Ford asked Tesla if he could help identify the
problem area. Tesla walked up to a wall of boilerplate and made a
small X in chalk on one of the plates. Ford was thrilled, and told him
to send an invoice.
The bill arrived, for $10,000. Ford asked for a breakdown. Tesla sent
another invoice, indicating a $1 charge for marking the wall with an
X, and $9,999 for knowing where to put it."

"Know Where Man" Urban Legend, hosted by snopes.com