Need Help A/C on the fritz, 1996 960

Chuck96960 · Post by **Chuck96960** » 13 Jun 2004, 13:13

OK heres the problem, I have 1996 960 Volvo, straight 6 2.4l, the A/C during the 70*- 75* temp runs fine. When the temp reaches 90* outside the A/C will kick off periodically some times it takes a long time to kick back on and some times it takes a few min. we have checked the refrigerant level and its up to the normal pressure. I have 66k miles on the car. its a very well kept car. So if anyone knows what's causing this problem it would be great.

Thank you very much
Chuck

ozzimark · Post by **ozzimark** » 13 Jun 2004, 20:15

maybe something wrong with a temp sensor somewhere?

Alann · Post by **Alann** » 13 Jun 2004, 22:48

Chuck, could be a simple vacume line, check all the lines from the firewall side and near the intake side,make shure they are conected. this car has a common leak in the vacuum motor, but that only happens when accelerating. the ECU can turn the AC compressor off if it senses any unusual load.

Alann · Post by **Alann** » 14 Jun 2004, 09:08

I forgot something, check A/C pressure switch (the one on the left of the3 sensors right in front of radiator ) and the pressostat and vaccum hoses. Clean all the contacts at the plugs Does your fan turn on?

SDIgroup · Post by **SDIgroup** » 17 Jun 2004, 16:13

Somewhat common problem on the 960 (mine included). The fan is not coming on when the A/C is requested. This causes the high pressure switch to cut power to the compressor when its threshold is met. This could be caused by the low and/or high pressure switch(es) not providing a ground to the fan relay because it/they are faulty, a ground is not being provided to them from the ECM to pass on to the relay (not common), or the relay itself is faulty (most likely).

All three of these pressure switches are located in the same place on the passenger side of the condenser front. The far left (looking at the vehicle) is the high pressure cutoff, the middle switch is fan low speed and the right one is for high speed fan.

Let me know if you need anything else on it.

SDIgroup2001 · Post by **SDIgroup2001** » 17 Jun 2004, 20:15

If you are so inclined and it's your own vehicle, you could always place a negative relay inline after the yellow/black lead from the cycling switch closing a ground to the high fan relay lead. This would cause the fan to operate at high speed whenever the A/C clutch was engaged (which, in my humble opinion is how CCOT systems should operate anyway) without interfering with the pressure safety switches.

Good Luck