I drive a DB1. My a/c doesn't do anything. What can I do to fix it? I dont know where the A/C compressor or a/c belt is located in the engine bay.. Should the compressor turn on when I press the a/c button? Should I just buy freon, dump it in, and cross my fingers?

ITS HELLA HOT!!!!!

 

The compressor is mounted below the power steering pump, almost under the engine.

Without a set of manifold gauges, [A/C gauges] it can be very hard to troubleshoot your A/C system, just dumping in refrigerant and hoping for the best is the same as tossing parts at a problem.

Most A/C shops will do a diagnostic for free, we do.

There are some things you can try, to eliminate electrical as the problem...

First thing to try is to jump the compressor clutch relay, unplug the relay, locate pins #30 and #87, use a 12V test light to confirm one of them is 12V+, the pin numbers/locations are on the relay, then use a paper clip, [or the like] to jump from#30 to #87, if you hear the compressor clutch engage, [click on] the clutch/coil and circuit to the compressor is good, if no click, you will have to access the compressor plug so you can jump power directly to it, to see if it is a clutch or circuit problem.

If the compressor clutch works, leave the jumper in place and start the engine, check the two lines going to/from the evaporator, the thinner one, [liquid line/input] should be hot and the thicker one, [vapor line/output] should be cold, very hot and very cold indicate a good refrigerant charge and you should have cold air from your vents.

Do not let the compressor run for too long before checking the lines, if the lines are not hot and cold, remove jumper if the refrigerant charge is low or system is empty oil is not being circulated and the compressor will be damaged if it is allowed to run for too long.

If the above seems to work, find and unplug the A/C pressure switch, and jump the plug, start engine and turn the A/C on, if the compressor turns on and the air is cold, replace the A/C pressure switch, if the air is not cold, turn off the A/C, you most likely have a low refrigerant charge, most likely because of a leak.

There is no point in recharging the system untill the leak is fixed, a nitrogen pressure test is needed to find the leak, we charge $20 for nitrogen pressure test.

In a lot of case a leak can be found by the oil stain around the leak, when refrigerant leaks out, it evaporates instantly, but the oil in the refrigerant is left behind leaving a stain.

Unlike a lot of other things in a car that can be diagnosed and repaired with not much more then a 12V test light and a few basic tools, proper A/C service requires at the very least a gauge set, a vacuum pump, a recharge cylinder, [over the counter "aerosol" cans of refrigerant can be used, if it is clean 100% refrigerant with no "sealers", oil is OK] a bottle of nitrogen and a leak detector.

If you do not have access to the above your better off going to a shop.

What ever you do, stay away from the REDTECs and Duracools and any other over the counter DIY A/C "repaid/recharge kits", they use propane or butane as the refrigerant and they are hydrocarbons, once in your system, they are not 100% removable, so if you ever have to go to a shop, you will be out of luck as it is the first thing they will check for, and if your system is contaminated with HCs, they will send you on your way, another problem is if you ever have to replace a part, [any A/C part] you will not get any warranty on that part, HC contmination VOIDS the warranty.

Last but not least, DIY kits that contain "sealers" claiming to fix leaks, do not work and will only gum up the system. 94

 

Thank you for the info!! Thumbs up times two

 

Hi All,

2004 Acura TSX (non-nav, 5AT). I know, I know, wrong forum, but I followed all of the instructions listed above and wanted to ask an additional question:

PROBLEM: A/C does not come on at any setting with the A/C button on or off. By not come on, I mean the compressor does not engage.

- A/C fuse (#30) in the dash box is fine.

- A/C compressor clutch relay is tested and fine.

- Jumper'd the A/C compressor clutch socket (pins 1 and 2) and the clutch engages the compressor fine. This bypasses the A/C low/hi pressure switch. The A/C blows cold air with the clutch jumpered and the lines coming out of the evaporator get very hot/very cold, so the system has a good charge.

- At this point, I removed the jumper and reinstalled the clutch relay. I then removed the A/C low/hi pressure switch connector and jumpered the connector pins....no A/C. Hmmm. When I connect a multimeter to one of the connector pins and body ground, I get something around 0.02-0.06 volts.

My assumption has been that when you press the A/C button on the climate control system, the car computer checks the A/C low/hi pressure switch condition, checks any additional interlocks, then sends control voltage (pins 3 and 4) to the A/C compressor clutch to engage the compressor (pins 1 and 2). So somewhere in that electrical system something is getting lost.

So now I am stumped and have a few questions.

1) Is my assumption above correct or are there other components/fuses/relays I can check?

2) Can someone check their A/C low/hi pressure switch connector by disconnecting it, hooking up a multimeter to the one of the connector pins (please check both) and body ground (or negative battery terminal), and letting me know what voltage they see when the climate control button is turned on and off?

3) Any ideas would be greatly appreciated!

-- whahappened

 

Try "rebooting" the ECU/ECM.
You do not need to know the voltage at the pressure switch, it makes no diff, when jumping, the switch is a simple binary, [2 wire switch] that has an off/on position, it is on when the refrigerant pressure is 30- 300 PSI anything below or above that the switch is off.

If it is in fact voltage, [as apposed to a ground] it is most likely a 5V referance, but again it makes no diff, what it is, if jumping the switch plug does not work, the switch is not the problem, try the reboot. 94

 

Not sure about the ECU, but did find the culprit (thermal protector):

Checked for continuity between pins 1 and 3 on the connector coming from the thermal protector...nada.

Found the thermal protector connector and checked for voltage, which was about 10 volts, which is good. Jumped the two pins and the compressor kicked right on. Need to replace the thermal protector.

For those who encounter the same problem, the part number is:

38908-RBB-A01 (~$50).

The replacement instructions can be found here (pages 151-153):

http://www.tsxclub.com/forums/conten...l%20System.pdf