Diode:
I spent a long time looking & I am told it could be wrapped in tape up above kick plate which is where the floorboard angles up? I see a wire harness down there. Everyone is chiming saying that these diode never go bad. I need to still find to test. I did find the brain box under lower pannel.

Dash Switch:
Is it possible the switch in dash is bad even though the light goes on both ac & compressor run off it ? I would like to remove switch and by pass it? Then I look a little closer and it looks like a major job to get it out of the dash? remove consule & entire dash?

No Luck:
This is all very frustrating and I will go to wrestling and start fresh in the morning.

Test Result:
I ran the ground test and get 13.5 on red on Pressure switch in key II position. Then I ran ground on blu/ yel & get 4.5. Bad ground.

 

Did you check the two fuses?

The thermostat is under the dash. I could not find an exact location. Follow the connection at the evaporator to find the thermostat. It shows a short wiring length from thermal sensor to thermostat module. Once you find it, unplug the unit and short across the Blu/Yel to Blu/Red harness wires. If thermostat is the problem, this should close the circuit (AC On) and allow a signal to ECM to engage compressor.

There are tests for the AC thermostat in the shop manual.

The thermostat prevents the compressor from running too long once evap temps reach freezing level, so it is necessary for proper AC function.

I have read of AC diode failure, but this does seem less likely than above and easier to check.

good luck

 

Your voltage is kind of high on red/wht wire. Just check the voltage across the battery terminals to make sure your volt meter is accurate. Or you may have typed in 13.5 instead of 12.5.

The 4.5 reading on the blu/yel wire is that ohms or Kohms?

Since ground is likely missing, unplug the a/c thermostat under the passenger dash. It has three wires. The blu/yel and blk/yel wire should both have 12V with the key in the II position. The blu/red should have continuity to ground.

 

This all looks good my daughter took the car to School for a few days.

No worries 2 other cars need work.

I was thinking of just adding a ground to the pressure switch? I was just thinking about this? A fix like this is fine; I do not think my daughter likes it much. I will go after last posted fixes of course.

However dad likes car because it is paid for and came from her grandmother / one owner. I am sure I will be driving it someday and that is fine as a 4 cycl. and back up ride.

John

 

Interesting! My 1994 EX is "hand-me-down" from my oldest daughter who drove this through under graduate school and "sold" to me when she purchased a 1997 Acura Cl ( Upscale Honda Coupe). I decided to keep the car as a spare and it's come in handy several times.

Recent fix of vibration under acceleration w/ new CV axles to replace Autozone axles has made the car a pleasure to drive once again.

I had some challenges w/ this car due to axle problem and I'm on my 3rd ECU w/ this car.

Your problem is very likely thermostat, or possibly AC diode. I would first make sure applicable fuses are good.

good luck

 

Both fues check OK.

The Thermostat was right there and you slide towards driver to take out.

When I Jump Blue/ Yel with Blue Red I get both fans to kick on with AC in on mode. AC did not kick in. Not sure if it should.

Blue /Yel & Black / Yel show 12 V or better. My new battery reads higher Volts then 12V. I was told this is ok.

Trying to check Continuity at the Blue / Red I ran a ground from the battery to my meter and I grounded the black to the ground and I put the red from meter on the Blue / Red with the meter in the Omhs 200 with sound setting. Not sure here I get no chime and get readings of 90. or so I can double check this again and the past ? on the oms above.

Have we established anything?

 

Blu/Yel to Blu/Red jumper should enable cooling fans and compressor to run (signal to the ECM should cause ECM to ground red/blu at compressor relay and enable compressor.

Jump result also confirms AC diode is good.

Jump results suggests faulty ECM or faulty red/wht wire from AC diode to ECM/AC pressure switch splice (see wiring diagram). Wiring defects are rare and this more likely indicates faulty ECM, IMO.

Jump results confirm AC pressure switch is closed, AC Switch is closed, and heater blower switch is closed.

One final check would be to ground the Red/Blu wire at the ECM connector. This should enable the compressor to engage any time ignition swithc is On. This would confirm the problem is due to no ground supply from ECM to compressor relay. Correct connector is A (26 pins). See Fuel and Emissions section wiring diagram and connector pin assignments.

good luck

 

TH - the ground path is not through the ECU on this part of the circuit. It grounds through the a/c switch, then the fan speed switch.

Does your volt meter have an open/closed setting? It would read open when your leads do not touch each other and closed when you touch the leads together? Just post your make and model volt meter on here and we can help you find the right setting.

 

Multi Meter is a

Ideal Test pro 360 Series Multimeter

Test-ProŽ Multimeter 360 Series

Are we thinking the AC switch and speed control is not grounded ?

If so & if I need to test or replace do I need to tear apart the inside consule and remove dash ? I was hoping it just pops out from the front?

 

I'm not sure if it helps but this is what happened in my brother in law car. 2000 Ford ZX2:
CCRM Fix