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A/C unit is blowing warm air

Tiny
ASEMASTER6371
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Okay, I sent another diagram for you. The 2 wires I circled need 5 volts. Tell me which one does not have power. That power comes from the ECM. You may have a bad ECM or the wiring to it.

Could you please tell me those readings as I cannot see them. It is way too small to see.

Roy
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Saturday, July 18th, 2020 AT 4:00 PM
Tiny
BWILKINSON05
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Roy,
I measured the three pins at the high side connector:
middle/top pin = 0V
left pin = 0V
right pin = 0-5V (this one wasn't consistent and would hold at 0V and then drift up to 5V)
I will measure again tomorrow.
Bret
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Saturday, July 18th, 2020 AT 5:55 PM
Tiny
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That is the issue. You need the correct amount of voltage at the wire for the system to work correctly.

Roy
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Saturday, July 18th, 2020 AT 6:20 PM
Tiny
BWILKINSON05
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Roy,
I remeasured the readings at the high pressure switch and show the following:

w/paperclip:
Top = Red = 0V
Left = Black = 0V
Right = Grey = 5V after it set

w/o paperclip with relay installed:
Top = Red = 0V
Left = Black = 0V
Right = Grey = 0V

I reviewed the schematic drawing you sent last Saturday at 11:29 AM, I believe the pressure sensor is the bottom right above the ECM. The grey shows 5V, the other two do not indicate a voltage. Does the red also need 5V? Where do you suggest I start with my testing?

Bret
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Sunday, July 19th, 2020 AT 12:02 PM
Tiny
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Yes, the red wire is missing the signal.

I attached the pin you need to test at the ECM for power to help determine whether it is a wring issue or the ECM.

I attached the connector as well. Check pin 14. Back probe it for 5 volts.

https://www.2carpros.com/articles/how-to-check-wiring

Roy

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Sunday, July 19th, 2020 AT 12:15 PM
Tiny
BWILKINSON05
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Roy,

I have removed the ECM rows/strips. Is mine on the green or blue strip? I found red wires with black stripes on both.
Bret
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Sunday, July 19th, 2020 AT 2:59 PM
Tiny
ASEMASTER6371
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At pin 14. There should only be one red wire. The other connector does not have a red wire at pin 14.

Roy
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Sunday, July 19th, 2020 AT 3:01 PM
Tiny
BWILKINSON05
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Roy,

I tested the green strip in all 4 locations i.E. 14 slots from the left, top and bottom and 14 slots from the right, top and bottom with paper clips with the key off and in the on position. All 8 tests = 0 ohms per the instructions. I used a paper clip in the ECM and paper clip in the high pressure sensor red line. Is this correct? Should I instead test for volts connecting a probe to the paper clip at the ECM and the other to ground?
Bret
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Sunday, July 19th, 2020 AT 6:47 PM
Tiny
ASEMASTER6371
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With everything hooked up with the key on, put the paperclip at the back of pin number 14 with the red wire and test for 5 volts. Red lead on the paper clip and black lead to a good ground.

Roy
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Monday, July 20th, 2020 AT 3:31 AM
Tiny
BWILKINSON05
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Roy,
I tested the #14 pin on the green strip top and bottom from each end - 0V for each test, total of 4 tests. This was the only strip with a red line near the 14 pin.
Bret
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Monday, July 20th, 2020 AT 6:05 PM
Tiny
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Okay, without that output, the A/C will not work.

Looks like you need an ECM.

Roy
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Monday, July 20th, 2020 AT 6:08 PM
Tiny
BWILKINSON05
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Roy,
10-4. Is a signal sent from the climate control module to the relay we can test? If there is and the signal is not being sent, would that explain why the relay isn't turning on the clutch.
Bret
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Monday, July 20th, 2020 AT 6:15 PM
Tiny
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It is because the ECM is bad.

Replace it and let us see if it fixes the issue.

Roy
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Monday, July 20th, 2020 AT 6:40 PM
Tiny
BWILKINSON05
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Roy,

I studied all our correspondence, now follow the schematic much better and also realized I did not back probe pin #14 properly. The first time I probed pin #14 from the green side not the back of the harness which I tested tonight with the harness connected to computer. I confirmed 0V - 1.2V still not enough and proving the ECM is bad. Where do you recommend I buy the ECM? I found one at Flagship1 for $150.00 with a lifetime warranty.
Thank you for your input.
Bret
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Wednesday, July 29th, 2020 AT 6:51 PM
Tiny
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You could go with that. Make sure it is programmed to your VIN number to work.

Roy
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Wednesday, July 29th, 2020 AT 6:55 PM
Tiny
BWILKINSON05
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  • 68 POSTS
Roy,

Good afternoon! I installed the ECM and followed the Passkey III - transponder ignition key set up process (10 minutes with key on, 5 seconds with key off - 3x) and my truck will not start. Do you have any recommendations?
Bret
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Saturday, August 8th, 2020 AT 12:46 PM
Tiny
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Is the theft or security light on after 10 second with the key on?

Roy
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Saturday, August 8th, 2020 AT 12:50 PM
Tiny
BWILKINSON05
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Roy,

The security light came on during the first 10 minute cycle and turned off after approximately 7 minutes. It did not come back on during the 2nd and 3rd 10 minute cycles.
Bret
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Saturday, August 8th, 2020 AT 12:55 PM
Tiny
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Okay, it is not a security issue.

I attached a diagram for you of the starting system. You need to see if the ECM is grounding the control side of the relay at the pin I circled.

Roy
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+1
Saturday, August 8th, 2020 AT 1:04 PM
Tiny
BWILKINSON05
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Roy,
We tested the starter relay in the fuse box with key on and off:
1. Bottom left pin (front of vehicle) with the back top right pin ranged = 9-11.5V
2. Top left pin (front of vehicle) with the back bottom right pin = 0v
3. Left top and bottom pin = 0v
4. Right top and bottom pin - range from 7-11.7v
Bret
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Saturday, August 8th, 2020 AT 1:33 PM

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