Weird Tranny Problem

For a while, my trany has been shifting hard when it is raining. Also (i think this is related) when on the highway, the speedomiter will swing back and forth when I let go of the gas. This morning on my way to work the trany decided to stop shifting. I think that there must be a loose wire. any ideas where I should look? I did find this on the forum that look promising:

on ALL a604 transmissions... there is a splice point... to make these transmission work properly...
that splices together a red wire from the Solenoid Pack, a red wire from the TCM/EATX, and a wire from
where the EATX Relay is plugged in...
The TSB Addendum was sent out to the production line...
Because they where having the Same problem... Right from the Get Go...
they spliced the three wires together, capping off the remaining wire... and electrical taped the
wires together and pushed them into the wire loom...

I'm not sure where this splice point is though. Any ideas?