Took out back up fuse for over twenty seconds with car on and off and jumped wires....fans only
I have no power to red wire going to compressor. Could ECM be bad and how can I check it

 

Also I have not been able to check ac switch on dash it does turn fans on and off

 

I think I may have more than one problem.
With thermostat unplugged the wires test fine when I plug it in the blue yellow has no power and the blue red has no ground.
I checked continuity across thermostat and got nothing.
When i I jump blue red to blue yellow only the fans come on I tried it both plugged and unplugged.

 

I hate suggesting you throw an ECU at the problem and not have it fix the a/c.

I want you try to unplugging the pressure switch. Use a jumper wire to ground the red/wht wire. Let us know if the compressor clutch engages.

Some of your tests with your volt meter are not making sense, so that is why I keep throwing out suggestions.

 

Grounded red white to pressure switch same thing fans no compressor

 

I don't mind trying anything I've had the car 4-5 years didn't do much long driving till last couple years so I didn't worry about it. I did a little trouble shooting last year....checked pressure it was fine so ran a hot wire to compressor ice cold air so I figured it was pressure switch. I googled it couple days ago and came across this forum glad I did u guys r very knowledgeable and I appreciate the help its saving me a lot of money

 

If you download that manual I referenced before, there is a series of tests for a compressor that is not working. We suggested most of the testing already. At the end of the diagnostics tree, they have two tests to try on the ECU electrical connector. You don't need the test harness they are referencing. The diagnostics are on page 22-14 and 22-15.

If you have voltage on the red/wht wire at the ECU, then replace the ECU.

For used ECUs, go to car-part.com. It is a website that searches junkyards that subscribe for used parts. You can sort by price or distance to see what is available in your area. The U-Pull-It junkyards are also good for used parts. You would need the year and model accords that have identical ECUs.

 

only have 2.5v on red/white at ecu im going to try to find diode and check it.Finally got manual i needed it is helping any other suggestions let me know thanks

 

After looking at wiring diagram again the red white splits after diode. I have 12v at pressure switch then I should have 12v at ecm again I only had 2.5v at ecm. Do I have a short or what could cause this?

 

One other thing the red blue wire, in the ECM harness, is in a different position than the diagram shows. It does have 12v.I found a ECM for $65 I'm going to get it and see if that make compressor come on. When i took ECM harness off iI found a broken pin and some corrosion. The broken pin goes to transmission lock silenoid, which explans why the D4 light either flahes or is off.Atleast ECM will help on gas milage, won't take long to pay for itself at todays prices. Hopefully it fixes A/C too. I'll let you know what happens.