Would installing this void my warranty?

This is in favor of Toyota. They show that damage was caused by the consumer and the warranty is void for modified items. There is little burden of proof here - the modification would be clear and apparent.

This modification would not void the warranty on the cylinder head, for example, but if there were electrical issues then Toyota might have a strong case for warranty exclusion.

 

It will depend on just what the electrical problems are, how electrically savvy the customer is, and how well the former can pull the wool over everyone else's eyes.

 

And the US Federal Government. (when in the US)

 

The warranty is offered in accordance with applicable laws, which does involve the US government, but the warranty is not between Toyota and the government. Even if the vehicle owner does not get satisfaction from Toyota, the next step is dispute resolution as spelled out in the warranty. There may also be state requirements, etc.

 

The best warranty is "one that you never use." Get the job done right in the first place.

It is a contract between the vendor and the consumer. Unless the vendor has violated laws and the product causes a life risking safety issue, law enforcement will not likely get involved. Cost for litigation will be in civil court.

Having seen many after market accessories installed by do-it-yourselfers an even so professed professionals, I can see how many of these can cause a voided warranty.

A fuse tap can cause a dead short and burn up the internal wiring harness if incorrectly installed. As I stated before in an earlier post, installing the tap in a reverse direction will negate the protection of the new fuse. A dead short in the new accessory would burn up both the accessory and the internal wiring harness of the vehicle. In that case the warranty is voided.