I’m looking to install an underseat subwoofer and will need a convenient spot from the driver seat to connect my ground cable. Without doing a total removal of the seat, I’m seeing there is some insulation under the carpet which makes it difficult to see much. Is there a factory ground point present close by I can use? I tried looking in the kick panel and there is also insulation present there so tough to find anything that I can reuse. I’m hesitant to drill holes under the seat since fuel lines might be present and it’s tough with all the under covers present under the car to see if anything is present there. Any ideas?
The electrical wiring diagram (more info) does show the location of every 'official' ground point in the car. I think these often use thread-rolling (rather than thread-cutting) screws, optimized for electrical contact. At least, that's been true in some cars I've worked on.
I would think the EWD is quite massive with a lot of diagrams. Before I go and do a subscription, which section would the grounding points be on?
In my paper 2001 EWD, it's Section I (letter between H and J, not "one"), titled "ground point". In the online EWD, I don't think the sections are numbered/lettered any more, you just look in the table of contents tree and click the Ground Point link. The EWD section on this PriusChat wiki page has some more info.
I found a gen 3 EWD online and saw that the closest factory ground point appears to be on the front seat belt pillar behind the panel about 3 feet above the Prius floor. I pulled the panel and saw one present there to see if gen 4s are similar and there it was. I also spotted a potential spot using the seat belt bolt behind the panel a foot above the ground as well. I’ll use a DMM to see if that’s a possible spot. It may needs to remove some paint. I’ll evaluate the seat bolt, but I’m leaning towards the seat belt bolt. Thanks to everyone for all the help.
