I've had many issues with my LS400 and just wanted to say this site has been invaluable at helping me resolve them! Thanks for the great replies to everyone active on these boards. I did these repairs myself.
Issue 1 - Dash lights (speedometer, RPM gauge) quit working.
Problem: Failing capacitors
Resolution: Bought replacement capacitors at Radio Shack, followed the instructions posted here for removing the instrument cluster and re-soldered the new ones in place of the old ones.
Cost to repair: $2.50 and 2 hours of work
Issue 2 - Rear antenna not raising/lowering when the radio is on
Problem: Plastic cord attached to antenna mast was broken in about four pieces
Resolution: Found instructions for replacing the antenna mast through these forums. Bought a new antenna mast on Ebay and replaced the mast.
Cost to repair: $15 for the mast, 1 hour of work
Issue 3 - Clock and Cab Temperature LCDs are blacked out though the Radio LCD still works. The Clock and Temp LCDs sometimes start working again when it's hot outside.
Problem: Common issue with the LCDs
Resolution: Found how to fix this through this site, though I have not yet made this repair due to cost of replacing the cluster or LCDs
Cost to repair: From $125 to $300, unknown amount of time
Issue 4 - Dash warning light remained on
Problem: Burned out taillight
Resolution: Replaced the taillight per the instructions of someone else on this board
Cost to Repair: $4.50 plus 30 minutes of labor