Electrical issues in an '06 Tacoma

Hello,
My cousin is having some problems with his 2006 Tacoma TRD Access Cab Manual. It started with the dome light ,then the compass, reverse lights , blinkers and finally the speedometer. all of these have gone out in the last week or so . He and I found a towing light controller that his friend put on when he borrowed the truck, which burnt two fuses while burning itself .
I have since pulled the controller and insulated the leads, as well as replaced the fuses, but those things are still not working. Chassis ground appears to be fine and the blinker lights work fine if used in the emergency flashing mode . The only DTC's are for Emissions and a speedometer malfunction . Ive been searching the web for almost a week, with no success so any help would be greatly appreciated.
Thanks,
Dan

 

Thanks for the link.
We went through every fuse and relay, it was only the two fuses related to towing that were out.

 

P0500 was the speedometer one,
the emissions were p0441, p0455, p0456

To the second poster there, you sound awfully sure that's what went out. I'm guessing you're speaking from experience?

Thanks again for the help guys.

 

When you say combination meter, does that include the tachometer?