Hello, I am in need of some guidance as to what is going on with the a/c wiring installed by a previous owner. He said it was working as is, but shouldn’t there be an amplifier up there somewhere?

My only internet access at the moment is my phone so I cannot get a clear enough diagram to even try to see what’s been done here. Judging by the research i’ve been able to do it seems like I’m missing some pieces that the P/O made due without.

I’m trying to avoid tearing the whole thing apart to figure out what those yellow wires are going to so i’m hoping someone here is more familiar with it. My only thought at the moment is to reconnect the yellow wire to the black/white and see what happens.. though i have almost zero confidence in that plan lol. Any input is greatly appreciated, thank you!





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There is supposed to be an amplifier, and about 7 wires run through it on most 1st gen 4Runner applications.
If you don't have a schematic for ac wiring lmk and I can post one up.
The good news is Toyota didn't make hardly any changes in the ac system for the 1984-1988 RN5/RN6, so you have a plethora of ways to get another used one.( i doubt new is available) In other words, an amp out of a 1985 2wd truck should work
I'd get one that includes the connector and enough wire to work with.
You do have the expansion valve and thermistor inside the evap box, and my guess is they unplugged one, or both of those, to by-pass with their yellow wires. I don't remember if you can remove the top or bottom of the box without disconnecting the lines running through the firewall. I'd strongly doubt it.

 

That is great info, thank you! Yeah if you could post up a schematic that would help me a ton. I can’t find one clear enough to read on my phone

There is a new amplifier on Amazon but it’s pretty expensive and i would still have to source the little harness/connectors. Hopefully i can find a used one somewhere.. thanks again!

 

Denso made a pretty solid electrical system for the a/c. I'd easily opt for a good used one with connector and some wires over a new one off Amazon.

These next phots are life savers. it's the connectors labelled in the schematic, and even show which wire is in what position. the way you view the connector is as if you were holding it and looking at the end that plugs in.


here's the schematic for the a/c amp. If you need other ac components let me know

 

Better image.

 

Here'd an interesting post made 16 years ago on IH8MUD.com. It may offer some insight into what the P.O. was trying to do.

The great unknown is why the P.O. felt it necessary to try this bypass the amp in the first place. They really are pretty solid. Once you get this retrofitted back you might uncover another issue that was the P.O.s original issue.

 

Thanks for the info, I appreciate you for taking the time to share it.