I've got a 2000 Accord V6 with the auto climate control. When the compressor is hooked into the harness, it won't engage. However, if you run power straight to the compressor it works great. So, what I need to know is, what might cause that? I'm working on it tomorrow and need to get some parts together today. I work at a junkyard, so I'm taking a temp control unit and a high pressure switch home. Are there any other switches or sensors that might keep the compressor from kicking in if they're bad?

 

If there is no coolant in the system, the compressor will not engage.

 

Bingo.

In the vast majority of cases where the compressor will not engage, the system is usually empty of refrigerant due to a leak or puncture. Check the pressures and charge the system as needed; I recommend adding leak detection dye to the system when charging so that you can pinpoint any leaks easily.

The most common leak point is the condenser; they often get punctured by rocks or road debris.

 

That was my first thought, so I fully charged the system but still couldn't get anything. Thanks for the suggestion though. :> I'll pick up some dye on my lunch break, but I'm pretty sure it's an electrical issue. Just checked the pressure again to be sure and it's right on the mark. Wouldn't that have dropped if there was a leak?

 

If the pressures are good, then it does sound like an electrical problem. Have you tested the harness to see if the connector is powered when the A/C is switched on?

 

I would check the AC thermostat if it has one. My 96 V6 had the same problem and it was the thermostat located in the evap area.

 

i think you mean evap temp sensor....

there are a few sensors in that circut that would prevent it from cycling on. there is also a compressor clutch relay which is switched on by the ecm.

 

It may not go on if the pressure is too high also(overcharged), but you say the pressures were spot on so the "thermostat" on the evap may be a good pace to start or a clogged expansion valve.

 

what are you static pressure reading high and low side,also readings while the system is on.

 

Wow, there's been a lot of work on this problem while I was gone. Last night was the first time this week I've had the chance to work on the problem. After checking everything, it turns out that the cooling fan was blowing it's fuse which wouldn't let the compressor engage. I can't believe I missed that blown fuse the first time through...I changed the high pressure switch, the dryer and the underhood fuse box. It works now, but the fix was easy...just the condenser fan is all that needed changing out. Thanks for all the help, I'm sure I'll be back when I do the 6 speed swap :D

 

glad it worked out for you.