Hi, I'm new here, and am trying to get the AC working on my nieces LX. V6, SINGLE CLIMATE CONTROL btw

It wasn't working, so I checked the compressor and the clutch had no ohms, so out it went. Her dad bought EVERYTHING for it from Rockauto, but the condenser wasn't correct, so I haven't replaced it all, but I got close.. compressor, evap, expansion valve, and O rings, dryer. Only thing I didn't do was condenser and pressure switch (see below!) Blew the lines out with a cleaner solution, and it came out VERY clean, it in fact had still held a charge, and was different pressures on both gauges, unlike now.

Everything is back together, vacuumed, and I am trying to put 134 in it (low side only!), but it just goes to 100psi and the compressor never comes on!? The condenser fan comes on and the inside is set to MAX AC and CC to full cold.

I found this thread https://www.hondaaccordforum.com/for...problem-61757/ and checked out the pressure switch.

I got nothing long ways, and closed circuit on the short side, I thought, EUREKA! REPLACE SWITCH... Till, I double checked and its CLOSED Blue to Blue/Red wire, (1-4 not 2-3) so thats ok, right?

I can jump compressor and it runs, and the pressure on the low side drops down to about 20psi and it finally took the rest of the first can of r134 I got for it, I closed the gauges, then stopped and came here to find out whats goin on.

I rotated the relays, no change. I checked for Vs to the compressor and nothing while running. The condenser fan comes on and the inside is set to MAX AC and CC to full cold)

I tried to get it to give a code for it (turn key off and press def and recirculate buttons then key on) and nothing happened, the Def button stayed solid color. (is this even for an 05??) My ODBII scanner says no codes also..

I really HOPE this has nothing to do with the idiot who took out the stock radio and put in a crappy sony, because we can't afford to replace it.. (The dash parts are still there, just the brain behind it is missing, and all the Climate buttons function properly too)

So, if the pressure switch is ok (is it?) and the relay swaps didn't change anything, what else is there besides that OP's eventual solution of a faulty PCM, missing radio, or, WHAT??

Been on this for a month, would like it out of the drive sometime soon lol

Thanks for any help/advice!

 

Suggest checking for voltages at compressor relay (pins 1 control & 4 power ) should both have 12V. If not check fuses (#12 under hood for power and #30 for control under dash).

If voltage present on both then control ground (pin 3 at relay) is not being supplied by ECM. This could be ECM, wiring, pressure switch, thermostat.

You need a wiring diagram and shop manual. If not check automanualsource.com for a download manual.

good luck

 

Ok, forgot to mention fuses 7 and 30 are good..

Is there any other way to test the pressure switch besides replacing it?

I will check for power at the relays as soon as its not melting shoes outside. (im in Tx too, but so far the closest gas is in OK! lol.)

 

Ok, I got 12v at both top and far side pins (I guess 1 and 4)

the center one 2 had 220ohms w/o a/c switch off, and 245ohms with it on.. -0.01v too?

3 seems to not have any ground at all, either with AC on or off..

Looks like the PCM isnt grounding it?

Where's the PCM and what pinout should I check for continuity to that post?

 

Ok, I found it, and Pin 27. with key on, engine off, I get WILD ohms #s. my analog one pegs past the infinate line, and the digital one says something like -1945 or something like that, when I touch black to pin and red to ground. Red to pin, black ground gets nothing.. odd, but...

Like the other threads poster, when I backprobed it, with relay in, engine ON, and AC on, testing for ground causes compressor to work..

So, like his, PCM bad, or is it possibly the thermometer in the dash is broke? It does have a dent in the vents.

Previous owner was a heavy smoker, so it MIGHT be something to check? (how??)

Thanks for your help Texas!

 

Backprobe Pin E18 at ECM to determine if ground is available w/ AC On. If no ground then fault may be in pressure switch or thermostat (evap temp sensor). Wiring, gauge control module, or relay module are also possible fault sources.

good luck

 

Ok, I think I got E18. No ground, but its a white or yellow and blue stripe wire..

If thats right, then what?

 

The ECM/PCM relay control wire is Red at A27; pin 27 of Connector A (31P gray connector) for a LX V6 with manual climate control.

For 4 cylinders with manual climate control, then the ECM/PCM relay control red wire is at E18; pin 18 of Connector E (31P white connector).

 

Its a V6, and I got OHMs at A27, and as above, when probed with engine running, the compressor comes on.

His next move was for E18, and I think I got it, I counted pins right to left looking AT plug side not wire side, then I flipped it to wire side and matched the slot. It was White or yellow with a blue stripe, not red tho...

I hate electrical issues lol

 

The Wht/Blu wire at E18 for a V6 is the ignition control wire for coil no. 3.