Good idea would be to get 2004 TL service manual.

I have 07-08 one, so your car might be different.


If image of this fusebox, or anything else is much different than your car, discard rest of this post and get 04 service manual (somewhere at this forum, use search) (tip: get manual anyways: use advanced search, on the bottom select to search only in 3rd gen forum)










According to that, #8 should be 15A fuse that supplies couple things, mainly through "PGM-Fi" relay #1 and #2. That is fuel injector stuff.

I would go under the dash and remove fuse #23 and two relays that supply fis, and then put fuse back.


If it doesn't burn this fuse anymore, then wires going to fuse box must be ok.

That's just the start.

You will need multimeter and/or many fuses.
Put/connect components back one-by-one.
You might also try disconnecting injectors. Maybe one of them is shorted. Inspect wires as mice really like them for some reason.

Getting system schematics would be helpful to know what exactly is on this system.