micky wrote

What are the devices in these two parts of a schematic

https://imgur.com/a/mnnzq3O

On the left is probably the lighting for the 2005 Solara trip computer.
The schematic calls it the Upper Console Panel Sub-Assembly which
I think is the part above the radio (but the schematic lists the clock
illumination separately and makes no reference to the outside
thermometer, so that just lives the sort-of trip computer.)

I understand the LEDs but why zener diodes,

Those provide a constant voltage across the leds so that the
intensity of the leds doesn't vary with the battery voltage.

and another diode

That protects against a reversal of the battery.

(since there is 12V DC at the top and ground at the bottom)?

The 12V is nominal and will vary with the state of the battery.

On the right is almost all of what the Toyota wiring manual calls the
combination meter, meaning the speedometer and other meters in
the instrument cluster. I aassume the "rheostat" is the thing it has to
adjust the brightnees, that the LED (or more than one) provides the
light, but what are the strange things at the bottom and to the right.

N channel MOSFETs
https://www.google.com/search?q=fet+schematic+symbol

They look like they are connected to transisors, but they have the
3 vertical lines, one of which in each set has a left-point arrow.

The left-point arrow arrow means that they are N channel MOSFETs.

The manual has a list of symbols and it has LED, photodiode
and zener diode, but not the strange things in that picture.

BTW, was this an appropriate post for Imgur?

Only if you are into ****ing electronics.

Most of their posts sseem to be more entertaining.

I though I had flickr and instagram but I can't find the login info.
I don't understand all this computer stuff.

Its actually electronics.