ECC not working at all where is the climate control panel connector located?

Tiny
CERRY
  • MEMBER
  • 1995 CADILLAC BROUGHAM
  • 66,000 MILES
Where is the plug for the Electronic Climate Control located?
Tuesday, April 16th, 2013 AT 11:44 AM

10 Replies

Tiny
JDL
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For the hvac system, have you tried entering self-diagnostics?

To enter diagnostic mode, turn the ignition on. Simultaneously press off button and temp button up arrow on ac heater control panel. Upon entry, a segment check will occur, and graphic display will indicate pointer no. -00.

To select pointer number, press up or down arrow on fan button. To diaplay ac system trouble codes, select pointer no. -02, then press out temp button. Current and history trouble codes will be displayed. Watch the hvac display on the dash. Let us know if there are any codes.

In your post, if you were asking about the electrical connector for hvac control, it's probably plugged into the back of hvac control.
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Tuesday, April 16th, 2013 AT 1:02 PM
Tiny
CERRY
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I can't enter diagnostic mode because the ECC will not come on, but thanks!

Would I find the electrical connector for the hvac control (ECC) that is "probably plugged into the back of the hvac control" under the dash or under the hood? In other words, is the back of the hvac control found under the dash, or is it found under the hood?
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Tuesday, April 16th, 2013 AT 1:15 PM
Tiny
JDL
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I see, For the heater control panel, the electrical connector is on the backside. Have to remove heater control panel from dash. Have you checked applicable fuses?
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Wednesday, April 17th, 2013 AT 7:23 AM
Tiny
CERRY
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Thanks. I have removed the heater control panel from the dash. I discovered that it is receiving some power as there is a small light inside the unit that comes on when the engine is running.

I have checked all fuses in the Instrument Panel Fuse Block and in the Underhood Electrical Center. All are fine. Are there any other fuse locations that I should check? If so, please describe the location(s).

I found a A/C COMP. RELAY in the Underhood Electrical Center. I seems to be fine. Could you tell me what the items in the picture marked with red arrows are?

Are there any other relevant relays I should check? If so, please describe the location(s).

Thank you!
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Wednesday, April 17th, 2013 AT 1:48 PM
Tiny
JDL
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Use a testlite on the fuse circuits in diagram. Even if fuses are good, if no voltage the circuit is still dead. Two of the fuse circuits are hot all the time, one goes hot with the key on.
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Wednesday, April 17th, 2013 AT 2:07 PM
Tiny
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All three tested good (as described) with the test light.
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Wednesday, April 17th, 2013 AT 2:54 PM
Tiny
JDL
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Other than check voltage and ground at the hvac control, I don't know where to go from here? You can check voltage at the hvac connector, brown wire and orange wire. Check the ground also.
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Thursday, April 18th, 2013 AT 10:54 AM
Tiny
JDL
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I forgot the wiring. Could be something wrong with the hvac control, I don't know?
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Thursday, April 18th, 2013 AT 10:56 AM
Tiny
CERRY
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Sorry to take so long to reply. I had to order parts, wait for them to arrive, install the new parts, and check everything out. Also, I am SLOW (but methodical)!

I checked everything that you suggested, and all checked out fine. That left the ECC Control Unit itself. I found a unit on EBay with the same serial number as my non-working unit at a great price. When it arrived, I installed it and found that everything was functioning. However, the AC compressor was not coming on, so I had no cool air. I discovered through the diagnostic feature in the PCM area (the HVAC area had no error codes), that the compressor clutch relay was bad and the compressor clutch circuit was also bad. (The diagnostic feature of the ECC Control Unit is GREAT!). Checked the relay (which was good prior to installing the new unit) and it was bad. Replaced the relay, but the compressor did not come on. The relay error code was gone, but the compressor clutch circuit error was still showing. So, I started over by checking the fuse in the inside fuse box (which had tested fine earlier), and found that the fuse was bad. Replaced the fuse and everything works great! All error codes are gone, too! I have run the AC for quite a while to make sure that the relay and fuse remained good. I must have done something during the checking out process and/or the install process to make those items go bad. But all is working great now!

Thank you for your help. I learned so much about a subject that had been completely foreign to me.
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Tuesday, April 30th, 2013 AT 9:24 AM
Tiny
JDL
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I'm glad you got it going your way. Good luck.
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Tuesday, April 30th, 2013 AT 12:56 PM

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