97 Es300: Ac Light Flashing: Two Options Which Is Right?

[total1]

1997 ES300 (200K+)

AC light flashing

Local, non-Lexus mechanic, has diagnosed that my 97 ES300 has either a bad Control Head ($1K-ish to replace) or bad compressor clutch (<$1Kish to replace). Both may be refurbished/remanufactured as necessary. No control codes help. Compress does not have any noise at all! Just doesn't stay engaged most of the time. Coolant pressure is fine (just replaced recently!) AC is cold WHEN it works. AC comes on/goes off in about a 1-2 second cycle. I can sometimes get the AC to stay on (30-40% or less of the time) by continuing to press the AC button when the AC disengages. Once connected, AC is cold and it sometimes can stay on for 30-60 minutes if driving on the interstate. Local driving (slowing down) almost always 'kills' the engagement.

So, is my problem the Control Head (electronics) or the compressor? How can I be sure?

TIA

[capnfred]

check the AC relay under the hood... burned contacts, do a search on the forums for the AC relay.. there is generic repalcement available from the auto houses.. or take it apart and clean the contacts.... you should be good to go.

capn

[total1]

check the AC relay under the hood... burned contacts, do a search on the forums for the AC relay.. there is generic repalcement available from the auto houses.. or take it apart and clean the contacts.... you should be good to go.

capn

Thanks, capn...

I've already replaced the Magnetic Clutch relay MG CLT [90987-02012] and this did not solve the problem. Is this the same or something different? Where and which fuse is it?

Again, TIA!

[carlexes330]

1997 ES300 (200K+)

AC light flashing

Local, non-Lexus mechanic, has diagnosed that my 97 ES300 has either a bad Control Head ($1K-ish to replace) or bad compressor clutch (<$1Kish to replace). Both may be refurbished/remanufactured as necessary. No control codes help. Compress does not have any noise at all! Just doesn't stay engaged most of the time. Coolant pressure is fine (just replaced recently!) AC is cold WHEN it works. AC comes on/goes off in about a 1-2 second cycle. I can sometimes get the AC to stay on (30-40% or less of the time) by continuing to press the AC button when the AC disengages. Once connected, AC is cold and it sometimes can stay on for 30-60 minutes if driving on the interstate. Local driving (slowing down) almost always 'kills' the engagement.

So, is my problem the Control Head (electronics) or the compressor? How can I be sure?

TIA

Check your refrigerant charge R134A you can get a kit from your local parts shop Pep boys,Autozone, Kragens even walmart sells it. Attach gauge and can to low side of system(The hose cannot be attached to the wrong side as different sizes) and have your AC on high speed and coldest setting and check the PSIG readings on the gauge should be between 25 and 45 PSIG if fully charged readings over or below those means under or overcharged .It helps if you do this check when the weather is warmer ie sunny and hot than cloudy and cold or raining . Hope that helps

[branshew]

Seems to me that the refrigerant is good since the AC is blowing cold when it works.

My office park floods during flash rain storms. When I had my 95 ES, I had driven through some deeper than average puddles getting in and out of the parking lot and if I recall correctly, my A/C light would flash when I did that and the system wouldn't blow cold air for a short term afterwards. I am guessing that the water shorted out the compressor until it dried. So.....

Check the wiring to the compressor. Make sure it is not corroded or abraded or shorted, and is otherwise able to deliver enough juice.

If yo can't find it, take it to a Lexus dealer and have them diagnose. I'd rather pay $100 to find out exactly what it is before paying $1000 to fix the wrong thing.