Air Conditioner Headache

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Bm7b5

Bm7b5

Joined
Mar 21, 2025
Threads
1
Messages
9
Location
Massachusetts
Hello!!
I've been searching through the forum, but haven't come across a similar situation. Thanks in advance!
2013 Land Cruiser
Purchased in late March 2025 w/103k miles.
After having it for a few days, I realized that the climate settings were at default (fan off and 75 degrees) each time I started the cruiser. I then realized it only resets to default when the car has been sitting an hour +
The AC blows cold and the heat works fine. The cold box and the cooling seats work
These are the 4 codes that were/are present:

23 - Pressure Sensor Circuit
47- Rear Air Mix Damper Control Servo Motor Circuit
49 - Rear Air Outlet Damper Control Servo Motor
88 -Rear Air Mix Damper Control Servo Motor Circuit on the From Passenger Side
Clear codes, immediately present.


Did some scouring on the web and people mentioned to ensure that the damper/filter in the glove box was operating correctly and properly fitted - The damper is functioning and the filter is seated properly
Found a person that was having same issues with his and he indicated that disconnecting the battery for a half hour appeared to correct the issue of resetting to default. I gave that a try and when I reconnected, I was no longer getting AC. - shorted something?!?
New additional code (in addition to the 4 others): 97 - BUS IC Communication Error


Dealer replaced the Pressure Switch
The AC was working again, but the original issue still present.
About a week after I noticed that the AC wasn’t kicking on until about 20 minutes into the drive. About a week later it was intermittently working, then nothing.
Brought it to Toyota. They looked at and said the condenser was leaking and needed to be replaced and quoted me 1800.
At this point, I wasn’t trusting them and brought it to a mechanic I know.
He checked the freon and it was low, and noticed the AC clutch wasn’t engaging.
He used his OB Computer system thing to force on the compressor - nothing.
Had the radiator and the condenser replaced (it was leaking)
I short the contacts at the relay and the compressor engages - isn’t blowing cold
Put the relay back in and the clutch isn’t engaging when the AC is turned on.

I'm wondering about the AC Amplifier, as well as, Techstream. Should Techstream have been used to reset the servos? Would that take care of 3 of the codes?

Any thoughts?
Thanks!
 
It’s worth trying the servo reset but your problems sound more significant than that.

Have you pulled the trim at the bottom of both front doors to look for evidence of water damage? Any time a 200-series has weird electrical things going on that should be done. If you don’t see pooled water or evidence of it, you should open the lower electrical connectors to look for corroded pins.
 
bloc said:
It’s worth trying the servo reset but your problems sound more significant than that.

Have you pulled the trim at the bottom of both front doors to look for evidence of water damage? Any time a 200-series has weird electrical things going on that should be done. If you don’t see pooled water or evidence of it, you should open the lower electrical connectors to look for corroded pins.
Click to expand...
Thanks for the suggestion of checking behind the trim, I’ll give it a look. Happy Thanksgiving!!
 
As bloc mentioned, definitely check both the driver and passenger kick panel areas. They have 2 or 3 (depending on side) large block connectors on each side, with 10mm bolt running down the centre keeping the connectors together.

Pull them apart and look for green crustyness and/or any broken pins.

You can go the extra mile and also unbolt/unclip the housings from where they attach to the inner fender, so that you can get to the rear side of the connector blocks as well. I had to take off the scuff plates, free up the big loom to give it more play to be able to do so. Its a bit of messing around but its do-able and would strongly recommend it

Buy Deox R5 or equivalent and a little paint brush. I had to spray into the connectors, use the brush to work it in and clean up corrosion. I also found on the rear side of one of the plugs a couple of wires completely broken off and a couple of pins still snapped off into the connector. You need to have a really good eye for the little pins to see if any have snapped off inside of the female sides of the connectors.

I didnt go to the effort of buying whole new blocks / harnesses, but instead I ran jump wires from side to side for any broken off pins/wires

Found the root cause to be the 2x sunroof drains (visible when you open the sunroof and pop your head up and check both front corners) being blocked and not allowing drainage. As a result, it would cause the flow of water to overflow and direct itself into the pillars internally. You can use trimmer line , compressed air or anything you can put together to clear out those drainage holes. Now no water gets in

Those block connectors run EVERYTHING. Radio stuff, air con related, seat related and so on.
 
570aus said:
Those block connectors run EVERYTHING. Radio stuff, air con related, seat related and so on.
Click to expand...

This.

One suggestion though... avoid compressed air to clear out the sunroof drains. You do not want those popping off their barbs on the tray.. that requires dropping the whole headliner. Has happened to at least one user here. Mechanical agitation (trimmer line or a tool made specifically for sunroof drains available cheaply on amazon) and more water flushed down the drains to get everything out.
 
Well, I checked out the connectors on both sides and except for the bit of crustiness on the lowest connector on the driver's side (see photos), they are all in great shape. I did take some electronics cleaner and a brush and cleaned the area and contacts.

I do still need to check out the back side of the block connectors to ensure there aren't any broken wires, that will have to wait till tomorrow though.

There's no signs of water intrusion/pooling/residue under the scuff plates

I also checked the sunroof drains. I poured water into both drains and they drain quickly out to the ground. I ran some trimmer line afterward and then rechecked- drains just as quickly/no back-up.

There's no change in the issue, still have the 5 codes and the compressor doesn't

How do I access the AC amplifier? I'd like to give that a look over as I've seen others showing trace damage on theirs.

FWIW, I'm an electronics technician with a good amount of engineering in my background - just minimal experience with automotive.

Thanks again!

IMG_2501.webp


IMG_2502.webp
 
That's enough corrosion that I'd be verifying continuity on all pins before replacing anything expensive. Good that it's dry now but that sure looks like it has seen some water or other oxidant in the past.

Where is this rig from? Salt sate?
 
I'll verify continuity in the morning when there's day light.

It's a southern New England Rig, amazingly clean, but yes - gets exposed to salt
 
Hate stating the obvious but its just i didnt see it noted in the thread.
I only have 2011 manual on hand right this second and looks like the AC system on these run on various fuses in the diagram. I imagine these were all checked (and probed on each end of the fuse):

10A A/C IG
7.5A A/C
50A HTR
10A ECU IG No2
50A RR AUTO A/C
50A PTC 1
50A PTC 2
50A PTC 3
 
570aus said:
As an example this shows how it all routes, junction connectors might be worth checking etc

Looks like everything does run to that AC amp if you cant find any fuse / wiring junction issues etc

System Diagram — 2011 Toyota Landcruiser V8-5.7L (3UR-FE) Service Manual | Operation CHARM

Detailed repair manual for the 2011 Toyota Landcruiser V8-5.7L (3UR-FE).
charm.li
Click to expand...
570aus said:
As an example this shows how it all routes, junction connectors might be worth checking etc

Looks like everything does run to that AC amp if you cant find any fuse / wiring junction issues etc

System Diagram — 2011 Toyota Landcruiser V8-5.7L (3UR-FE) Service Manual | Operation CHARM

Detailed repair manual for the 2011 Toyota Landcruiser V8-5.7L (3UR-FE).
charm.li
Click to expand...
Thanks! I was able to find the electrical diagrams for the 2013 through your link. Extremely helpful! I realized I pulled my Fluke out of the rig earlier in the week and left it at work, so I have to wait till Monday to really drill down into the circuits. My cheap Harbor Freight is good for verifying pwr, but for more involved efforts, it's just annoying.
 
570aus said:
As bloc mentioned, definitely check both the driver and passenger kick panel areas. They have 2 or 3 (depending on side) large block connectors on each side, with 10mm bolt running down the centre keeping the connectors together.

Pull them apart and look for green crustyness and/or any broken pins.

You can go the extra mile and also unbolt/unclip the housings from where they attach to the inner fender, so that you can get to the rear side of the connector blocks as well. I had to take off the scuff plates, free up the big loom to give it more play to be able to do so. Its a bit of messing around but its do-able and would strongly recommend it

Buy Deox R5 or equivalent and a little paint brush. I had to spray into the connectors, use the brush to work it in and clean up corrosion. I also found on the rear side of one of the plugs a couple of wires completely broken off and a couple of pins still snapped off into the connector. You need to have a really good eye for the little pins to see if any have snapped off inside of the female sides of the connectors.

I didnt go to the effort of buying whole new blocks / harnesses, but instead I ran jump wires from side to side for any broken off pins/wires

Found the root cause to be the 2x sunroof drains (visible when you open the sunroof and pop your head up and check both front corners) being blocked and not allowing drainage. As a result, it would cause the flow of water to overflow and direct itself into the pillars internally. You can use trimmer line , compressed air or anything you can put together to clear out those drainage holes. Now no water gets in

Those block connectors run EVERYTHING. Radio stuff, air con related, seat related and so on
Click to expand...

570aus said:
As bloc mentioned, definitely check both the driver and passenger kick panel areas. They have 2 or 3 (depending on side) large block connectors on each side, with 10mm bolt running down the centre keeping the connectors together.

Pull them apart and look for green crustyness and/or any broken pins.

You can go the extra mile and also unbolt/unclip the housings from where they attach to the inner fender, so that you can get to the rear side of the connector blocks as well. I had to take off the scuff plates, free up the big loom to give it more play to be able to do so. Its a bit of messing around but its do-able and would strongly recommend it

Buy Deox R5 or equivalent and a little paint brush. I had to spray into the connectors, use the brush to work it in and clean up corrosion. I also found on the rear side of one of the plugs a couple of wires completely broken off and a couple of pins still snapped off into the connector. You need to have a really good eye for the little pins to see if any have snapped off inside of the female sides of the connectors.

I didnt go to the effort of buying whole new blocks / harnesses, but instead I ran jump wires from side to side for any broken off pins/wires

Found the root cause to be the 2x sunroof drains (visible when you open the sunroof and pop your head up and check both front corners) being blocked and not allowing drainage. As a result, it would cause the flow of water to overflow and direct itself into the pillars internally. You can use trimmer line , compressed air or anything you can put together to clear out those drainage holes. Now no water gets in

Those block connectors run EVERYTHING. Radio stuff, air con related, seat related and so on.
Click to expand...
Getting those blocks out is a real pain. I'm walking the tight rope of frustration/not breaking anything. It's a Zen and the Art of.... moment
 
570aus said:
Hate stating the obvious but its just i didnt see it noted in the thread.
I only have 2011 manual on hand right this second and looks like the AC system on these run on various fuses in the diagram. I imagine these were all checked (and probed on each end of the fuse):

10A A/C IG
7.5A A/C
50A HTR
10A ECU IG No2
50A RR AUTO A/C
50A PTC 1
50A PTC 2
50A PTC 3
Click to expand...
Thanks, I had verified them all previously before I had anyone else take a look at it and did so again after reading your post. They are all good. Once I get my good meter from work on Monday, I'll start digging into each leg of the circuits using the diagrams that 570uas provided (2013 one).
 
As an aside, and maybe a SQOD...

After cleaning up the electrical boxes in the Driver and Passenger side footwells, does it make any sense to liberally apply some dielectric grease in them as a prophylactic measure against future corrosion?

At first blush, it seems like a good idea, but since Toyota didn't use any, I'm wondering if it would do any good.

Thoughts?
 
gaijin said:
As an aside, and maybe a SQOD...

After cleaning up the electrical boxes in the Driver and Passenger side footwells, does it make any sense to liberally apply some dielectric grease in them as a prophylactic measure against future corrosion?

At first blush, it seems like a good idea, but since Toyota didn't use any, I'm wondering if it would do any good.

Thoughts?
Click to expand...

I just use deox d5 (or maybe its r5 i gotta check can) which leaves a film/coating remaining after, but yeah im sure thatd be good too
 
gaijin said:
As an aside, and maybe a SQOD...

After cleaning up the electrical boxes in the Driver and Passenger side footwells, does it make any sense to liberally apply some dielectric grease in them as a prophylactic measure against future corrosion?

At first blush, it seems like a good idea, but since Toyota didn't use any, I'm wondering if it would do any good.

Thoughts?
Click to expand...

That has been suggested in the past but my feeling is it makes any future work more difficult. And as you said, toyota didn't feel it was necessary. Then again, they felt our sunroof drains were adequate..

IMO this logic applies more for rigs with no previous damage though.. if there is already corrosion started, it could make sense to apply something that can keep it in check, even if the leak has been addressed.
 
570aus said:
I just use deox d5 (or maybe its r5 i gotta check can) which leaves a film/coating remaining after, but yeah im sure thatd be good too
Click to expand...
bloc said:
That has been suggested in the past but my feeling is it makes any future work more difficult. And as you said, toyota didn't feel it was necessary. Then again, they felt our sunroof drains were adequate..

IMO this logic applies more for rigs with no previous damage though.. if there is already corrosion started, it could make sense to apply something that can keep it in check, even if the leak has been addressed.
Click to expand...

After some research I am seriously considering DeoxIt DN5S-6N for cleaning:

Link on Amazon

1764549410767.webp


Followed with DeoxIt Shield SN5S-6N as a prortectant:

Link on Amazon

1764549556988.webp


Maybe a winner combo?
 
The first can should be plenty as an all in one on its own, it cleans and protects , similar to the stuff i used.
 
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