Edmunds Answers

Voted Best Answer

  • avatar karjunkie 07/07/10 10:39 am PST

    OK, then the next step is to disable or replace the the shorted sun load sensor. It is located over the top of the glove box in the top dash panel. There are two of these sensors up there and the one on the far right is the sun load sensor, while the one at the defroster ducts is the auto headlamp sensor. To replace the SL sensor, you just pop the grille out (it snaps into place) and the one you are lookin for has 2 wires BN and PK/BK. It contains a photovoltaic diode that is sensitive to light and is supposed to give an extra boost of cool air based on the amount of sun light but I do not think it will cause you any problems if you disconnect it. There is really no way to test it. You can try and unplug it and see if it makes any difference. Once unplugged, you can try to run the self test again, but if everything works normally, just leave it unplugged. Let me know what you find and we can continue if your problem persists.

Answers

  • karjunkie 07/06/10 12:53 pm PST



    • First check these fuses in the under dash fuse panel. No.18 (30amp),no. 16 (15amp), and no. 23 (15amp). If they are all good then you can run a self test on the system. Here are the instructions on doing this.


      To enter the self-test, press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The display will show a pulse tracer going around the center of the display window. The test may run as long as 30 seconds. Record all DTCs displayed.
    • If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given.
    • If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Improper Operation.
    • To exit self-test and retain all intermittent DTCs, push the blue (cooler) button. The control will exit self-test, retain all intermittent diagnostic trouble codes and then turn OFF (display blank).
    • To exit the self-test and clear all DTCs, press the DEFROST button. The vacuum fluorescent display window will show 888 and all function symbols for one second. Then, the EATC control assembly will turn OFF (display blank) and all DTCs will be cleared.
    • Always exit the self-test before powering the system down (system turned OFF).
    • Intermittent DTCs will be deleted after 80 ignition switch ON cycles after the intermittent condition occurs.

    Let me know if you get any codes.

  • drtripower 07/06/10 5:49 pm PST

    I checked the fuses. All were good. There was no fuse no. 23, although all 15amp fuses are good.
    I tried to run the self test (EATC) following your instructions, but is would not run. I did run this test two months ago and it came back with a code, solar radiation sensor bad ground. After running the test the ac started blowing cold and has been cold since until two days ago. We put guages on and the charge is full. After playing with on/off, max cool, I can get it to blow cool air but its not what it should be.

    thanks for your help,

    Lou

  • karjunkie 07/07/10 10:39 am PST

    OK, then the next step is to disable or replace the the shorted sun load sensor. It is located over the top of the glove box in the top dash panel. There are two of these sensors up there and the one on the far right is the sun load sensor, while the one at the defroster ducts is the auto headlamp sensor. To replace the SL sensor, you just pop the grille out (it snaps into place) and the one you are lookin for has 2 wires BN and PK/BK. It contains a photovoltaic diode that is sensitive to light and is supposed to give an extra boost of cool air based on the amount of sun light but I do not think it will cause you any problems if you disconnect it. There is really no way to test it. You can try and unplug it and see if it makes any difference. Once unplugged, you can try to run the self test again, but if everything works normally, just leave it unplugged. Let me know what you find and we can continue if your problem persists.

  • drtripower 07/07/10 9:50 pm PST

    Thank you, I will do this in the next day or so and will get back to you.

    thank you,

    Lou

  • drtripower 07/08/10 5:36 pm PST

    I removed the grill cover above the glove box in order to remove the SL sensor, but there was nothing under the cover. Just a hole on the left side. There was a sensor near the grill cover on the top, guess this is a light sensor.

ADVERTISEMENT

Top Mercury Grand Marquis Experts View More

Rank Leader Points
1. MrShift@Edmunds 150
2. karjunkie 125
3. zaken1 75
4. morin2 70
5. scanman1 50
6. tony78 45
7. boomchek 35
ADVERTISEMENT