A/C Clutch not engaging

SonicVQ

Good troubleshooting!

I data logged my AC pressure sensor and it was also 1.0 volts with the AC on and blowing cold with outside temps at 32C / 86F.

Please update us when you know more.

Mxzx

Will do!

Mxzx

So Nissan dealer wants to replace the compressor for $1700, with no guarantee that will fix the problem!!

SonicVQ

In your first post you said:
"I can run 12v to the compressor and clutch will pull and a/c runs."
Did the air get cold?

If it did, I don't think the compressor is bad.

Have the AC pressures been checked?

Mxzx

So the dealer had the car for 2 weeks. They replaced the compressor after they claimed they had power going to the mag clutch, still no clutch engagement.
They took the new compressor off, put original back, recharged system, and I took the car back without paying a dime. Still no a/c.

Nissan Tech Support claims this is not the first time they have come across this in a 370Z.

SonicVQ

This shouldn't be this difficult to figure out... it seems like the dealerships are lost unless they have a trouble code.

For example, changing the compressor was throwing parts at the problem. If the old compressor did engage when the clutch had 12v, it makes no sense to replace it with a new one.

If this was my car, I would:
• Verify the compressor ground with an ohm meter.
• Measure the current in the wire going to the compressor clutch using a current clamp. (very easy to do)

If the A/C relay (soldered to the inside of the IPDM/ER) has pitted contacts, you can measure the proper voltage, BUT the contacts may arc and create a high resistance, greatly reducing the current and the clutch can't engage.
- just like when the battery has corroded connections and you try to start the car.

Have you tried the IPDM/ER "Auto Active Test"?
This will verify if the IPDM/ER can control the clutch.

In auto active test mode, the IPDM E/R sends a drive signal to the following systems to check their operation. • Oil pressure warning lamp
• Front wiper (LO, HI)
• Parking lamps
• License plate lamps
• Side maker lamps
• Tail lamps
• Front fog lamps
• Headlamps (LO, HI)
• A/C compressor (magnet clutch)
• Cooling fan (cooling fan control module)

Operation Procedure
1. Close the hood and lift the wiper arms from the windshield. (Prevent windshield damage due to wiper operation)

NOTE: When auto active test is performed with hood opened, sprinkle water on windshield beforehand.

2. Turn the ignition switch OFF.
3. Turn the ignition switch ON, and within 20 seconds, press the front door switch (driver side) 10 times. Then turn the ignition switch OFF.

CAUTION: Close passenger door.
4. Turn the ignition switch ON within 10 seconds. After that the horn sounds once and the auto active test starts.
5. The oil pressure warning lamp starts blinking when the auto active test starts.
6. After a series of the following operations is repeated 3 times, auto active test is completed.

Mxzx

SonicVQ that is all GREAT info!!

You are the first person that I have found that even knows where the A/C relay is. I took the IPDM E/R apart, but saw nothing that looked like an A/C relay.

It is acting exactly like you say, the dealer said he had power to clutch with test light, but not enough current to engage clutch.

I will try the test tomorrow and report back.

Is the best option for the relay to just get another IPDM E/R off eBay or something?

Thanks again for the good info!!

SonicVQ

I'm glad you found my post helpful.

I think an IPDM/ER from the scrap yard or ebay would be a cost effective choice.

Here is the link to the Nissan part 284B7-1BN6B:
https://parts.nissanusa.com/p/Nissan...4B7-1BN6B.html

Click on "What this fits" and it shows "Nissan 370Z 2011, 2012, 2013"

To avoid paying the "Z tax" the same part number is also used on:
INFINITI EX35 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017
INFINITI EX37 2013, 2014, 2015, 2016, 2017
INFINITI G25 2011, 2012, 2013
INFINITI G37 2011, 2012, 2013, 2014, 2015
INFINITI G37X 2011, 2012, 2013
INFINITI Q40 2014, 2015
INFINITI Q60 2014, 2015

(from: https://parts.infinitiusa.com/p/8958...4B7-1BN6B.html)

Now you have some options and I suspect the G37 IPDM/ER will be a lower cost, more available and it's the same part.

Mxzx

I was thinking the same thing! That is about all that is left to make it not work.

Thanks for the part numbers! I'll report back with results.

Mxzx

So we ran the Auto Active Test today, and guess what?? The a/c relay clicks on/off 3 times after the headlights!!

Makes no sense why clutch won't engage. A/C pressure at 75F is 110 on both high and low side.

Still think a IPDM E/R swap may fix it?

I'm totally at a loss.

Mxzx

Got a IPDM E/R on the way to try out, not getting my hopes up!

Mxzx

So I put the new/used IPDM E/R in and the car would not recognize the key? It had the steering wheel icon come up and would not do anything.

Any ideas?

I did not disconnect the battery and try again for fear the original one would not work again and car would be disabled.

Mxzx

After spending weeks at the Nissan dealer they found a couple broken wires from pressure switch and a bad Auto Amp. A/C blowing cold now!