piggydog

Felt sorry for my baby prelude. Tach was jumping all over the place and I was going 75 mph and the car starting jerking and losing power (Consider level 1 as the lowest and 4 is the highest for the fan control). Oh yeah my A/C wasn't cold

Thanks for any input

zumer2007

What year is your car? Before 1994? Was an R-134a upgrade or any other work done to your AC system?

At 75mph, your engine is under heavy load from wind drag, so it's more susceptible to any additional resistance. One scenario could be that a problem with your AC system is loading your engine more noticeably than when driving at slower speeds. Because your AC isn't cold, what may be happening is that debris in your refrigerant might be fully or partially clogging the system, thus burdening your AC compressor from operating freely. In turn, this would drag down your motor because the compressor is effectively braking your engine through the drive belt. (The erratic jerking may be the drive belt slipping.) I would first determine that refrigerant is running freely through the system before operating it again. If your refrigerant is clogging somewhere, you could blow your compressor; and even worse, the high pressure side of the system might be dangerously over-compressed in this condition.

You should turn to a professional AC mechanic to determine if this is the case and to fix it correctly. He would have gauges that can check for correct pressures within your system. I don't recommend doing this yourself because of the possibility that abnormal and dangerously high pressures may exist in your AC system if this is the case.

piggydog

thx. Runs perfectly when the fan is at level 2. I'll looking into your sugg. or just pray it doesn't get any hotter. LOL

zumer2007

Another scenario is that your fan switch (or the connectors to the switch) may be corroded and intermittent. On my '92 Prelude, the compressor is controlled by a series of two switches: The AC on/off button, and also the fan speed control. It could be possible that the fan switch's contacts on the "2" setting is good, but the "3" setting is intermittent. An intermittent connection might be switching your compressor on and off rapidly, leading to the symptoms you're experiencing...

ETA: I can't figure out the connection between the problem occurring at 75mph and fan speed 3... Two different systems...


Modified by zumer2007 at 7:05 AM 8/20/2007

M2B4

wow lol u should diagnose my ac problems.

op: do u ever have problems with the green ac light coming on?

piggydog

92 prelude. thx again for all input. I just sweat like a pig for the rest of the summer and stick my head out like a dog. lol.

piggydog

92 prelude. thx again for all input. I just sweat like a pig for the rest of the summer and stick my head out like a dog. lol.