I have a 2008 TL with 152,000 with a yellow top battery.

After driving for 90 minutes on the highway, I stopped for 1 hour and drove 15-20 minutes on the highway.

My turn signals would not light up, (hazard lights did work)
the rear defroster light was on but not working,
the wipers would not work in the 2 low speeds but would for the fast ones.

I reached my destination and tried to get out but the power locks would not work and I had to manually lift the lock to get out.

After 1 hour I left and everything seemed to work all right.

The only other electrical issue was that the car's electrical system shut down completely while at a stop light. I then put it in neutral and it restarted with no problem. This happened in the Summer time before I got the yellow top.

Any suggestions?
Thanks in advance.

 

Sounds like water in the MICU and/or ECU.

Check the car's sunroof drains by pouring water in them; blow them with compressed air.
Other sources of water are a bad windshield seal (in rain or car washes) or water from the A/C (usually in the ECU) if the condenser outlet hose in front of the passenger-side floorpan is plugged.

There are several threads with photos here on AZ about water leaks into the MICU and ECU.

G/L.