Hi there, I have a 1996 honda accord ex coupe. About a week ago my a/c was working perfectly when I was running some errands. When I came back out to my car and started it up again, the a/c didn't work anymore. The compressor does not engage nor do the fans turn on. The vent fan works normally, but the cooling capability was suddenly nonexistant. I have done some trouble shooting. First, I ran a jumper wire to the compressor and got that to work. Checked the connectors for the relays and found I have power. Found one bad relay, replaced that, and still no change. I checked the refrigerant levels on the low side, those were normal. I tested the pressure switch conector and have power there. I ran a jumper wire from the pressure switch to a ground. The compressor engages and fans come on, no cold air, but the high side line gets cold. Could anyone point me in the right dierection and tell me what other problem(s) there might be?

 

Good job.

Based on the information ( jumping the pressure swtich causes the system to activate ) provided I would say either a bad pressure switch or low refrigerant charge.

The high side line ( the smaller diameter line ) should never get cold. The low side line ( the larger of the two ) should get cold.

I would recover the system and charge to the factory specification. Recheck the system.

 

Thanks, so by recovering the refrigerant and then recharging it resets the switch per say.
if that dosent work and i have to replace the pressure switch do i have to reclaim the system?

 

1 thing you might want to try before getting into recharging and changing components is this. since you know everything works when you used a jumper, its very possible it is a blown fuse causing the AC not to work. Id hate to see someone waste the time and money required to recharge and replace parts just to find out it still wont work. If it is not the fuse, continue with your current plans.

PS, If you are going to recharge your AC system by yourself, follow the steps in this write up to properly charge your system.
https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/%5Bfaq%5D-how-charge-your-c-air-conditioner-conditioning-system-home-1665946/

 

When jumping the pressure switch causes the system to activate the problem has been isolated.

The problem is either the pressure switch or the actual system pressure.

 

The pressure switch is a constantly reactive switch. Once pressures are within range the switch closes and the system activates. I have never seen a faulty A/C pressure switch.

 

^ yep, when your system gets too low the low pressure cut-out switch engages and keeps your compressor from turning on.

when you have a low pressure situation the A/C system works great. starving the system makes it perform really well. but there is a fine line between starving and just not enough refrigerant.

sounds like a quick recharge should get you cooled off. I've got a slow leak on my accord and I just add a little whenever it gets below starving.

 

But whats blowing my mind is that when i jump the pressure switch the fans compressor turn on but the system dosent kick out any coold air. If im correct the pressure switch does one thing and one thing only. It tells the system if there is enough 134a in the system to run, but when i bypass the switch it turns on but no cold air. could there be a differant problem i should investigate?

 

If you jump the pressure switch and the system turn on it is probably low on charge AND PROBABLY THE REASON IT DOESN'T BLOW COLD AIR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

This my friend is impressive. I had no clue about that. Where'd you get your information?

 

Im sorry i upset you. But i have put at least a can of 134a and the guague is on the border(red zone) over charge walmart 134a recharge kit guage.

 

What is the vent temperature?

 

With the pressure switch being jumped the temp on max is 70 and around 78 when i turn max. Are you thinking a/c thermostat?

 

Can you get/buy/rent a set of r134a manifold gauges? If so, put them on and check the pressure at idle and then again at say 2000 RPM with the compressor engaged (jump the switch for a few minutes if you need to).

Post your results.

 

Ok i have the guage the system shows danger till i enguage the compressor and it bottoms out at low. It does appear but im not quite sure yet its looks like when i go to recharge the system the guage dosent move. Does it look like i have a leak some where to you guys?

 

Ok i put a can in with the compressor jumped it got around 65 degrees at the vent but pressure was border line low fill. I think there is a leak in the system.

 

I fixed a similar problem this morning, but I don't know if it will help. I KNEW the relays and fuses worked properly because I had them diagnose my A/C. Now once I replaced the relay the compressor kicked on. My gauge also showed to be in the danger zone at first also. But what I did was let the fan run for 5 min on both recycled outside air & circulating inside air. Then I turned the A/C on and did the same thing. Let it run for 10 min and it's blowing cold. I also have a small leak in the discharge line from the compressor to the evaporator. Now, I'm no expert BUT it really, really seems like it's low on R134a. And it really makes a difference if u shake the can while u hold the trigger. Hope this helps.