1996 Integra dash clock dead, head unit dead

I got the car with a factory head unit and an aftermarket Pioneer CD
changer installed. I replaced the factory head unit with a Pioneer CD
player head unit. I did not hook the CD changer to the new head unit.
I bought a Pioneer to Acura wiring harness adapter for the new head
unit and soldered and taped the connections between the Pioneer harness
and the adapter harness. My adapter harness then plugs into the
factory harness connector. All was perfect for years.

I recently had a leak at a tail lamp that caused some rainwater to run
into the trunk. I fixed the leak and removed the interior carpet to
clean it. Since the carpet was out, I decided to remove the obsolete
CD changer. It was mounted in the trunk with several wires running
under the trim on the drivers side, under the driver's dash, and into
the head unit area. There were 3 power wires connected to the old CD
changer. Black, yellow, red. The black went to a grounding bolt near
the changer. The red and yellow ran to the factory stereo harness
connector, where they were spliced into two wires there then wrapped
with electrical tape.

I unscrewed the changer's black ground lead from the chassis and
clipped the red and yellow about 6 inches from the factory harness
connector. I taped the newly cut tips of the red and yellow wires so
they could not short to anything. At his point I found that my head
unit would not turn on and my dashboard digital clock is dead.

I removed the tape from the two wire splices at the factory harness
connector and unwound the splices from the factory wire. I put new
tape on the bare copper of the factory wires. This did not help.

I put a multi-meter on the black and red pins of the Pioneer connector
that plugs into the back of my head unit. I get 12.25 volts when the
key is in the accessory position. I do not understand why the head
unit will not power up. There is a 10 Amp fuse on the head unit and it
is fine. I even continuity tested it with the multi-meter.

Normally, I would think that I somehow toasted my head unit. But the
fact that the clock is out makes me think there's a mischievous wire
somewhere back there.

What should I try next?

 

make sure the black ground lead is grounded properly.