QuestionHello Roland, how's it going?
ok, here's a long story made short.
last year my car's A/C rubber hose got a leak. Waited until this year to replace both discharge and liquid lines since I was at it. Pulled a vacuum, held very well, try to recharge system but now my clutch is not engaging at all. Checked fuses and relays, all good; jumpered clutch and it did work and I had cold air in the car. Pressure while compressor running was around 40 PSI on the low side and 160 on high side. Checked for continuity between A/C pressure switch plug and the power distribution block at the A/C relay terminal and I found continuity in the pins on top. I'm guessing pin 1 is top right, pin 2 is top left and pin 3 is bottom, right? If so, I have 5V on pin 2 and I think pin 1 is ground, I have no idea what pin 3 is for.
So after all this checks I'm assuming that the only thing that can be faulty is the pressure switch. Since I decided to replace both hoses I unscrewed the switch from the old hose and screwed it back on the new one and hand tightened it and then just gave it a 1/4 of a turn with a wrench since I read that I only needed 5Nm.
So is my suspicion is correct, is there any way I can check the switch to see if it's working like it should? I read that it should have continuity between the prongs but since this one has three, I'm not quite sure if the same applies or not. Also what is the pin 3 for on the plug?
Thank you very much in advance, I have been trying to figure this out for over a week now and still no luck.
AnswerPS I mailed the pages this afternoon. Good luck on the repair. I know Richmond from 50 years ago where my wife-to-be went to college.
Hi Cesar,
I have the '94 manual for the LH cars to reference.
The three pins on the switch are: 5V reference voltage (violet/white), the signal voltage of the pressure reading (dark blue goes to pin 48 of the pcm) and a signal ground reference (black/light blue goes to pin 4 of pcm).
There is no spec as to what voltage signal it should read in order to power up the compressor, rather there is a fairly lengthy procedure to evaluate the system (pressures/ambient temp/discharge pressures, etc). I can xerox copy and mail those to you. Let me know a postal mailing address. If you would be so kind as to mail me back three 42-cent stamps after you get the pages that would be appreciated.
Roland
