No voltage at compressor/No AC
 

95 EX manual 4-cylinder.

My compressor clutch is not coming on in my 95 EX. I have tested the wire that goes to the compressor with a multimeter and it is not receiving voltage. With the key in the on(2) position, I noticed that the fans do not spin when the AC button is pressed. Both fans should spin when the AC button is pressed. Both fans spin temperature wise relating to cooling the engine. I do have the repair manual and started troubleshooting the compressor starting on page 22-14 to 22-15. It lead me to "Substitute a known-good ECM and recheck. If symptom/indication goes away, replace the original ECM." I have another accord, 94 LX 4-cylinder so I grabbed that ECM, plugged it into the EX and same thing, compressor doesn't engage. Leads me to think the ECM isn't the issue. I really thought I was getting somewhere as I was working the flow chart! Replaced relays (condenser fan relay and compressor clutch relay) and still not working. I also have extra relays I pulled from the JY.

#4 fuse is fine (7.5)
#8 fuse is fine (7.5)
#34 fuse is fine (15)

Extra notes: A/C is fully charged and tested with manifold gauges. When I jump the compressor clutch from 12+ battery to clutch compressor kicks on. Ambient temps yesterday were in the 70's and the temp from the vents reached down to 36 before I unhooked the jumper.



Please help!

Disconnect the A/C pressure switch and jump the terminals on the connector. If the system comes ON, you've found your issue. If not, you may have a bad A/C thermistor. (common Honda issue)

Will test when I get home today. Thanks!

I have tested the ac pressure switch and the compressor nor fans powered on. I also checked the plug leading to ac thermostat for voltage and continuity and it checked out fine. To go a little further I also measured the voltage between the blue/red wire to ground on the 14p heater control panel and there was battery voltage. Checked the a/c switch for continuity and it was fine. Any other ideas? I am thinking whatever the ac switch on the panel "kicks" and powers up the fans and compressor clutch is haunting me.

At the a/c pressure switch wire harness side connector, the red/wht wire should have 12V to ground (use a bare metal bolt as ground). The blu/red wire should have continuity to ground (use same bare metal bolt as ground). Make sure the key is in the II position when you do this test.

Test for continuity between the two pins on the a/c pressure switch.

Red/white wire has 12volts and blue/yellow wire has no continuity. Also checked the switch itself for continuity and it tested good.

Got the wire color wrong on my last post, it is blu/yel.

Next step is at the thermostat electrical connector. The blu/yel and blk/yel wire should both have 12V to ground (bare metal bolt for ground again). The blu/red wire should have continuity to ground using the same bare metal bolt as your ground.

Diagnosed with key in "on" position:

The blue/yellow and black/yellow both have 12volts. The blue/red has no continuity whatsoever. So as the flow chart states I should be looking at replacing the ac thermostat?

Thanks for all the help. Flowchart suggested to replace a/c thermostat so I went to the pull-a-part yard and pulled four of them just in case some didn't work. Replaced and now the A/C fans and compressor is working! So issue was with the A/C thermostat. Thanks again.

I'm glad it is fixed.

You should have had continuity to ground on the red/blu wire going to the thermostat. I wonder if you had the fan set to off, or the a/c switch wasn't set to ON during the testing?