My car overheats when I use the AC and I am in traffic. The car has a mild 302 with aluminum heads making 297 RWHP. Stock cooling system. I believe I have 192 degree thermostat installed.
What I have done so far:
1. Grounded pin 17 on CCRM. High speed fan turns on.
2. Traced CCRM pin 17 to PCM, pin 32. Grounding PCM pin 32 and the high speed fan turns on.
3. Used an ODBI tester. No engine error codes. It did report a CMOS(?) error. I ASSUME that us because of the SCT chip.
4. ODB1 engine self test can run the the low speed and then high speed fan.
5. ECT disconnect, high speed fan runs.
6. Jumper ECT connector, high speed fan runs.
7. Engine warms up to about 180 degree, ECT connected, the low speed fan starts.
8. Turn on AC max, low speed fan continues to run.
The AC is on and blowing cold air. So I figure the PCM had engaged the AC compressor clutch. When turning on the AC the engine RPMs are raised by the PCM. Because of the aluminum heads I have not let the engine reach 226 degrees to see if the ECT will trigger the the high speed fan. What inputs does the PCM need to turn on the high speed fan when the AC is on?
What I have done so far:
1. Grounded pin 17 on CCRM. High speed fan turns on.
2. Traced CCRM pin 17 to PCM, pin 32. Grounding PCM pin 32 and the high speed fan turns on.
3. Used an ODBI tester. No engine error codes. It did report a CMOS(?) error. I ASSUME that us because of the SCT chip.
4. ODB1 engine self test can run the the low speed and then high speed fan.
5. ECT disconnect, high speed fan runs.
6. Jumper ECT connector, high speed fan runs.
7. Engine warms up to about 180 degree, ECT connected, the low speed fan starts.
8. Turn on AC max, low speed fan continues to run.
The AC is on and blowing cold air. So I figure the PCM had engaged the AC compressor clutch. When turning on the AC the engine RPMs are raised by the PCM. Because of the aluminum heads I have not let the engine reach 226 degrees to see if the ECT will trigger the the high speed fan. What inputs does the PCM need to turn on the high speed fan when the AC is on?