Why would both cool packs have no fire to the number three cylinder and all others are fine

 

Welcome to the forum

I assume a 4cyl dual spark plug engine, and 1989 to 2001 Ranger

But please post engine size and year of Ranger

Ford uses a Waste Spark system
So spark plugs for #2 and #3 cylinders spark at the same time, and both spark plugs in each cylinder spark at the same time, no alternating, popular Myth

To balance a 4cyl engine #1 and #4 are at Top Dead Center, TDC, at the same time, then 180deg later #2 and #3 are at TDC
So #1 and #4 spark at the same time, and then #2 and #3 spark at the same time.

1 Spark is Wasted, because only one cylinder will be on Compression stroke and needs a spark, the other is on its exhaust stroke so doesn't need a spark but also doesn't hurt anything.

The coil packs only have 2 coils inside
One coil spark #1 and #4 at the same time
The other coil sparks #2 and #3 at the same time
These are wired in series, so depend on each other

If you don't "show" spark on #3 then there should be no spark on #2 either.
If you have spark on #2 then reverse the wires on the coil pack, and #3 should now work and #2 would be dead, that would indicate a coil pack issue
If #3 stays dead then spark plug or wire issue