1986 Camry Air Conditioning Help - Toyota Nation Forum : Toyota Car and Truck Forums

toored · 05-17-2008, 10:55 AM

The A/C light flashes and the compressor will not engage. This is an intermittent problem. Alldata says that only 2 things can cause this problem: belt slippage or a loss of signal from the speed sensor on the back of the compressor. Belt slippage is not an issue. I have replaced the compressor, receiver/drier, expansion valve, the speed sensor, the high pressure switch, and converted to R134. All to no avail.When the ignition is placed off and then the engine restarted, the compressor will engage for about 2 seconds, then trip off again. Some days the system works great.I have confirmed the correct freon charge. Any assistance with this issue will be greatly appreciated, as it's starting to get hot again! Thanks!!

***toyomoho*** · 05-17-2008, 03:27 PM

Have you tested the magnetic clutch (if not replaced), clutch electrical relay, A/C amplifier, etc. Alldata may have info on testing these items.

If you think the A/C system is otherwise OK, try applying 12DC directly to the compressor clutch and determine if starts and runs OK.

fredk · 05-17-2008, 10:24 PM

what are your pressures?

toored · 05-18-2008, 09:26 AM

The pressures were 300/25PSI at 68 deg F. at 2500 RPM. I forgot to mention that I have also replaced the amplifier. I have applied 12 volts directly to the compressor and it engages normally. The new compressor came with a new clutch and I had the problem with the old compressor/clutch combo as well, so I don't suspect the clutch. I thought I may jumper the speed sensor wire directly to pin 7 of the amplifier to see if the speed sensor wire is damaged/open between the sensor and the amplifier. Also jumper from pin 10 of the amplifier directly to the clutch to see if that wire is damaged. Any other ideas are appreciated. Thanks again!

***toyomoho*** · 05-18-2008, 11:51 AM

Send a private TN message with an email address. Can reply with info that should help diagnosis this system.

fredk · 05-18-2008, 07:16 PM

condenser efficency really shows with that 300 at 68 degrees, the 25 is just a little low but the 300 is mighty high, i had to fill my 88 with 134a and the dryer partially plugged and i had a really high hi side, touch the condenser outlet and see if its alot cooler than the inlet with the fan blasting, turn the inside blower on medium and put it on rec with the windows up

toored · 05-19-2008, 10:22 AM

Yesterday when it was about 78 degrees I began shaking down the wiring harnesses in an attempt to find a broken wire/bad connection. As I shook the harness close to the amplifier, the compressor started engaging and disengaging as if there is either a bad connection at the amplifier or a broken wire near there. But, before I could narrow down which wire, it stopped and I couldn't get the compressor to engage any more, regardless how much I shook or flexed the harness. So I figured the circuit was open; that would make it easier to find later. However, I got in the car this morning, temp at 55 degrees, turned the system on and it worked great all the way to work. I shook down the harness again and I could not get the system to fail, no matter how much I flexed it! This is as frustrating as hell! Now I'm not sure what to do. I will de-pin each wire at the amp connector and check each one, but I'm wondering if there may be a partial blockage in the system somewhere that's causing it to work OK when the ambient temp is low, then fail when it's hot. Thanks again.

dockdweller · 06-10-2008, 04:59 PM

Did you get this resolved? We thought it might be that any general fault would cause this and at one point jumpered the high pres switch. Since it started working thought that might be it.

I may have narrowed it to the square relay which I think was intermittent. We stuck a piece of paper inside it to push over the switch which also seemed to fix the problem as it worked for another day. It stopped but maybe only because the shim wasn't thick enough. I have a new one on order from Toyota now and hope this fixes it.

ikenga25 · 09-06-2008, 10:13 AM

I started having this same blinking problem after i replaced my compressor. the auto electrician diagnosed the problem to be caused by an electrical short problem. the offending cable was taped and problem was solved. So check your wire harness.