Positive battery terminal
 

The OEM postive battery terminal on our LS400 are tired after 20 years.

It can be replaced without purchasing an entire harness assembly.
https://cimg7.ibsrv.net/gimg/www.clu...6ac2970b2f.jpgBottom side of original OEM positive battery terminal. Not in best condition
https://cimg1.ibsrv.net/gimg/www.clu...f91b0acae0.jpgOxidation and acid build-up have permeated the terminal stud base internally...some resistance and voltage drop going on here.
https://cimg7.ibsrv.net/gimg/www.clu...d283b3c47b.jpgThe stud is affixed to a small square base inside the assembly and makes contact within the frame when the postive battery cables are are tightened. This allows build-up of oxidation internally that cannot be easily cleaned. Replacement is the best option. Aftermarket vendors such as QuickCable offer a better terminal but it will not fit under the OEM positive battery clamp plastic covee. I will send original to QuickCable to see if they can engineer and produce a replacement .
https://cimg3.ibsrv.net/gimg/www.clu...17060f85e0.jpgBatteey terminal cleaner...Inexpensive item worth acquiring
https://cimg6.ibsrv.net/gimg/www.clu...92a98e1bf9.jpgNew OEM positive battery terminal installed after cleaning positive battery post. The cap on the end of post cleaner opens to expose a wire brush..
https://cimg8.ibsrv.net/gimg/www.clu...b8abe5f66f.jpgPositive battery terminal assembly P.N. 90982-05037... This is for 1999 LS400....
https://cimg3.ibsrv.net/gimg/www.clu...852cede4e7.jpgLexus exploded parts diagram depicting battery terminal....don't forget your nuts.

Negative clamp is not a separate service item. Check out my post on negative clamp and grounding solutions.

Great information presented in a clear manner. My positive terminal is showing age as well.

These replaceable components are one of the reasons I love Toyota. I like other brands too (mainly Ford and VW) but if that were a Ford you'd be buying an entire battery harness to fix the terminal.