If I understand this correctly: The LS has an integrated climate control mixing heating and a/c.
If - as in my case - the a/c line to the rear has pinholes and needs to be repaired, can I drive the car without a/c in the meantime and just use the heater as a stand-alone? Or would running the climate system ruin something in the a/c in this given situtation?

 

Correct, the LS430 runs the A/C even when you operate the heater, mainly as humidity control. Suggest you pull the A/C compressor fuse to keep it from sucking in air through the pinholes.

 

thanks for the info
but can you tell me exactly which fuse I should pull?
I checked the fuse location in the manual and there are numerous fuses marked "airconditioning" - nothing that would indicate the compressor

 

To remove power from the A/C compressor clutch and keep everything else running, it's best to pull the A/C compressor relay, instead. See diagram below for the location of this relay...

 

much obliged