1HDFT transplant in a 97 LX450 - A/C not working (4 Viewers)

[Bungy teckel]

Hi,

Since the transplant we have not been able to get the AC working from the console.

Have been looking into that issue for a while now, hitting a wall. The compressor engage when it is hard wired and blows cold. Ground was tested properly on the Amplifier and on the relays. The compressor relay and the engine coolant relay have been tested and we fell/hear they engage when turning the engine on.

The car can start in D and therefore we think the issue is with the starter cut relay that we should bypass. We are 95% sure this is the issue however, have not been able to access it easily to confirm. anyone been through that? anything else we have not considered? Is there a way to access this relay without removing the entire dashboard, it looks it s above the evaporator, hard to access.

Somepicture of the diagrams and location of the S11 (start cut relay).

 

[NeverFinis]

anything else we have not considered?

Yea, Fix your park/neutral position switch if your vehicle can start in D, or any other gear besides Park or Neutral.

I did an LS swap, and my A/C works, and my park/neutral position switch is functioning properly as designed.

 

[Bungy teckel]

Thank you @NeverFinis. So I was able to get the 12v from the park/neutral, however, we also aren't able to get S11 starter cut relay to click despite testing with adding/removing 12v from the A2 A/C dual pressure. also noticed the C16 compressor relay gets really hot during the testing which could be a sign that relay does not work or surge..
Any suggestions to access these 2 relays (above the evaporator) without removing the dashboard entirely so we can test them out?

One other thought that there is no more ECU in my setup, that should not have any impact but maybe we are missing something.

Thanks!

 

[NeverFinis]

I think those relays are really tough to remove, without pulling the dash or the evaporator itself.

I would backprobe the A/C Amplifier first and its connections before doing that. It is on the evaporator side, and can be removed.

I am a bit confused about the A/C Dual Pressure switch. If the pressure is within range, it should allow 12V through. You shouldn't need to add/remove 12V there. Why?

Doesn't the C16 relay getting hot point to the fact that current is flowing through it, which means the Starter Cut relay (S11) is also working?

Check for +12V at pin 3 on the A/C Amplifier. This means the A/C Dual Pressure Switch is working, passing Voltage through to the Start Cut Relay.

Check for GND at pin 7 on the A/C Amplifier. This means the A.C Amplifier has the right signals to turn on the A/C Compressor.

 

[ceylonfj40nut]

Are using the 1fzfe harness/ parts of ECU? The AC in 80s are connected to temp sensors on the engine as well. Protects engine when overheating by cutting AC off. Perhaps this is not your issue. Thought I would mention regardless.